diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -14,6 +14,9 @@
 
 # Changelog
 
+* 4.6.0.0
+  - Renamed `definitely` to `totally`.
+
 * 4.5.0.0
   - Replaced usages of `KnownNat` with a new `NatToInt` class to avoid inefficient Integer https://github.com/louispan/data-diverse/issues/8.
 
diff --git a/data-diverse.cabal b/data-diverse.cabal
--- a/data-diverse.cabal
+++ b/data-diverse.cabal
@@ -1,5 +1,5 @@
 name:                data-diverse
-version:             4.5.0.0
+version:             4.6.0.0
 synopsis:            Extensible records and polymorphic variants.
 description:         "Data.Diverse.Many" is an extensible record for any size encoded efficiently as (Seq Any).
                      "Data.Diverse.Which" is a polymorphic variant of possibilities encoded as (Int, Any).
diff --git a/src/Data/Diverse/Which.hs b/src/Data/Diverse/Which.hs
--- a/src/Data/Diverse/Which.hs
+++ b/src/Data/Diverse/Which.hs
@@ -7,7 +7,7 @@
       -- ** Construction
     , impossible
     , impossible'
-    , definitely
+    , totally
     , pick
     , pick0
     , pickOnly
diff --git a/src/Data/Diverse/Which/Internal.hs b/src/Data/Diverse/Which/Internal.hs
--- a/src/Data/Diverse/Which/Internal.hs
+++ b/src/Data/Diverse/Which/Internal.hs
@@ -28,7 +28,7 @@
       -- ** Construction
     , impossible
     , impossible'
-    , definitely
+    , totally
     , pick
     , pick0
     , pickOnly
@@ -188,10 +188,11 @@
 impossible' :: Which '[Void] -> a
 impossible' a = case a of {}
 
--- | This function is useful to type restrict something (usually a continuation monad)
--- that returns a polymorphic type to return (Which '[])
-definitely :: f (Which '[]) -> f (Which '[])
-definitely = id
+-- | This function is useful to type restrict something that returns a polymorphic type
+-- to return (Which '[]). Eg. use thishat to prove at compile time that a
+-- finished continuation monad has no more unhandled holes.
+totally :: f (Which '[]) -> f (Which '[])
+totally = id
 
 -- | Lift a value into a 'Which' of possibly other types @xs@.
 -- @xs@ can be inferred or specified with TypeApplications.
diff --git a/test/Data/Diverse/ManySpec.hs b/test/Data/Diverse/ManySpec.hs
--- a/test/Data/Diverse/ManySpec.hs
+++ b/test/Data/Diverse/ManySpec.hs
@@ -327,7 +327,7 @@
             afoldr (:) [] (collectN x (casesN y)) `shouldBe` ret
             afoldr (:) [] (forManyN (casesN y) x) `shouldBe` ret
 
-        it "every piece can be mapped into a different type in a Functor-like fashion with using 'afmap'" $ do
+        it "every hasLens can be mapped into a different type in a Functor-like fashion with using 'afmap'" $ do
             let x = (5 :: Int) ./ (6 :: Int8) ./ (7 :: Int16) ./ (8 :: Int32) ./ nil
                 y = (15 :: Int) ./ (16 :: Int8) ./ (17 :: Int16) ./ (18 :: Int32) ./ nil
                 z = ("5" :: String) ./ ("6" :: String) ./ ("7" :: String) ./ ("8" :: String) ./ nil