Toothpaste tube letters (3)
I believe the answer is:
'toothpaste tube letters' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ada that I've seen before include "Computer language; girl's name" , "Palindromic girl's name" , "Woman" , "Girl's name, one letter short of a man's name" , "Programming language" .)