fill in the blank

Short definition from Wiktionary

Noun

1. 1
   A language exercise in which one or more words are replaced with a blank line and the reader is tasked with supplying a valid replacement.
2. 2
   A placeholder allowing for any of a variety of possible answers or a single elicited answer.

Verb

1. 1
   To complete a single fill in the blank question.
2. 2
   To complete an interruption, ambiguity, or vagueness in understanding, perception, or context.