diff --git a/R/f-eval.R b/R/f-eval.R
index 18bb76a..dc1b69b 100644
--- a/R/f-eval.R
+++ b/R/f-eval.R
@@ -10,10 +10,18 @@
 #' \code{.env} and \code{.data}. These are thin wrappers around \code{.data}
 #' and \code{.env} that throw errors if you try to access non-existent values.
 #'
+#' You can also provide additional sources of data with the
+#' \code{explicit} argument. It should be a named list containing one
+#' or several lists. Each of them will get a pronoun equal to their
+#' name. Contrarily to \code{data}, sources in \code{explicit} are not
+#' directly accessible. Therefore you have to explicitly qualify them
+#' with the relevant pronoun to access these data.
+#'
 #' @param f A one-sided formula. Any expressions wrapped in \code{ (( )) } will
 #'   will be "unquoted", i.e. they will be evaluated, and the results inserted
 #'   back into the formula. See \code{\link{f_interp}} for more details.
 #' @param data A list (or data frame).
+#' @param explicit A named list of lists (or data frames).
 #' @export
 #' @examples
 #' f_eval(~ 1 + 2 + 3)
@@ -36,6 +44,13 @@
 #' f_eval(~ .data$cyl, mtcars)
 #' f_eval(~ .env$cyl, mtcars)
 #'
+#' # Additional pronouns can be added by supplying explicit:
+#' f_eval(~ .iris$Species, explicit = list(.iris = iris))
+#'
+#' # The data contained in these sources can only be accessed
+#' # explicitly, through the pronoun. Direct access will fail:
+#' \dontrun{f_eval(~ Species, explicit = list(.iris = iris))}
+#'
 #' # Imagine you are computing the mean of a variable:
 #' f_eval(~ mean(cyl), mtcars)
 #' # How can you change the variable that's being computed?
@@ -49,17 +64,29 @@
 #' # take one more step of explicitness. Unfortunately data$((var)) is
 #' # not valid R code, so we need to use the prefix for of `$`.
 #' f_eval(~ mean( `$`(.data, ((var)) )), mtcars)
-f_eval <- function(f, data = NULL) {
+f_eval <- function(f, data = NULL, explicit = NULL) {
   expr <- f_rhs(f_interp(f))
 
   if (!is.null(data) && !is.list(data)) {
     stop("`data` must be must be NULL, a list, or a data frame.", call. = FALSE)
   }
 
+  if (!is.null(explicit)) {
+    if (is.null(names(explicit))) {
+      stop("`explicit` should be named", call. = FALSE)
+    }
+    if (!all(vapply(explicit, is.list, logical(1)))) {
+      stop("`explicit` should contain lists or data frames", call. = FALSE)
+    }
+  }
+
   parent_env <- environment(f)
   env <- new.env(parent = parent_env)
-  env$.env <- complain(parent_env)
-  env$.data <- complain(data)
+
+  sources <- c(.env = parent_env, .data = list(data), explicit)
+  for (source in names(sources)) {
+    env[[source]] <- complain(sources[[source]])
+  }
 
   eval(expr, data, env)
 }
diff --git a/man/f_eval.Rd b/man/f_eval.Rd
index 199b9f3..4619af3 100644
--- a/man/f_eval.Rd
+++ b/man/f_eval.Rd
@@ -4,7 +4,7 @@
 \alias{f_eval}
 \title{Evaluate a formula}
 \usage{
-f_eval(f, data = NULL)
+f_eval(f, data = NULL, explicit = NULL)
 }
 \arguments{
 \item{f}{A one-sided formula. Any expressions wrapped in \code{ (( )) } will
@@ -12,6 +12,8 @@ will be "unquoted", i.e. they will be evaluated, and the results inserted
 back into the formula. See \code{\link{f_interp}} for more details.}
 
 \item{data}{A list (or data frame).}
+
+\item{explicit}{A named list of lists (or data frames).}
 }
 \description{
 \code{f_eval} evaluates the \code{\link{f_rhs}} of a formula in its environment.
@@ -24,6 +26,13 @@ When used with \code{data}, \code{f_eval} provides two pronouns to make it
 possible to be explicit about where you want values to come from:
 \code{.env} and \code{.data}. These are thin wrappers around \code{.data}
 and \code{.env} that throw errors if you try to access non-existent values.
+
+You can also provide additional sources of data with the
+\code{explicit} argument. It should be a named list containing one
+or several lists. Each of them will get a pronoun equal to their
+name. Contrarily to \code{data}, sources in \code{explicit} are not
+directly accessible. Therefore you have to explicitly qualify them
+with the relevant pronoun to access these data.
 }
 \examples{
 f_eval(~ 1 + 2 + 3)
@@ -46,6 +55,13 @@ cyl <- 10
 f_eval(~ .data$cyl, mtcars)
 f_eval(~ .env$cyl, mtcars)
 
+# Additional pronouns can be added by supplying explicit:
+f_eval(~ .iris$Species, explicit = list(.iris = iris))
+
+# The data contained in these sources can only be accessed
+# explicitly, through the pronoun. Direct access will fail:
+\dontrun{f_eval(~ Species, explicit = list(.iris = iris))}
+
 # Imagine you are computing the mean of a variable:
 f_eval(~ mean(cyl), mtcars)
 # How can you change the variable that's being computed?
diff --git a/tests/testthat/test-f-eval.R b/tests/testthat/test-f-eval.R
index fd56df7..89b90b1 100644
--- a/tests/testthat/test-f-eval.R
+++ b/tests/testthat/test-f-eval.R
@@ -36,3 +36,17 @@ test_that("f_eval does quasiquoting", {
   x <- 10
   expect_equal(f_eval(~ ((quote(x)))), 10)
 })
+
+test_that("look into explicit pronouns", {
+  expect_equal(f_eval(~ .mtcars$cyl, explicit = list(.mtcars = mtcars)), mtcars$cyl)
+})
+
+test_that("data of explicit pronouns cannot be directly accessed", {
+  expect_error(f_eval(~ cyl, explicit = list(.data = mtcars)))
+})
+
+test_that("fails when explicit is malformed", {
+  expect_error(f_eval(~ ., explicit = list(mtcars)), "should be named")
+  expect_error(f_eval(~ ., explicit = list(pronoun = list)), "should contain lists")
+})
+