the characters that were once kept in bottom half of a compositor's type case
"The digital typesetter struggled to replicate the unique, slightly uneven texture of lowercase letters as they appeared when cast from the physical bottom half of an old compositor's type case."
Alternative spelling of lower case
"The programmer fixed a typo where she had accidentally typed lowercase letters instead of uppercase ones in her code header."
To convert (text) to lower case.
"The developer ran a script to lowercase all the email addresses before saving them to the database."
relating to small (not capitalized) letters that were kept in the lower half of a compositor's type case
"lowercase letters; a and b and c etc"
in lower case
"The teacher reminded us to write all our letters in lowercase for the practice worksheet."