All my dictionaries give numerous definitions for the words 'pin' and 'pinned,' but neither of the following and I'm wondering why.

pin (verb), slang, meaning 'to see or watch.' Often used (mostly by young people) in the 1950s and later, as in "Let's pin the flicks" = "Let's go to the movies/go to to see a film."

pinned (adjective). Said of eyes whose pupils are exceedingly contracted, i.e. unusually small, especially in reference to the eyes of heroin users who are high, when the occurrence is common. "With pinned eyes like those, he's got to be on smack."