Aside from the scheme example in the sibling reply, ruby has had a lambda, as a special kind of proc, for a very very long time and it is similarly not a "real

Aside from the scheme example in the sibling reply, ruby has had a lambda, as a special kind of proc, for a very very long time and it is similarly not a "real lambda." Honestly it's likely that for most of the history of the term it's been more used for "incorrect" meanings than "correct" ones.