Here are the possible solutions for one in a prompt box clue
Answer
Clue
Relevancy
cue
Clue
Prompt's prompt
Definition
to prompt an actor
cuer
Clue
One in a prompt box
and
Clue
Impatient one's prompt
Definition
a conjunction indicating addition
baldspot
Clue
One might prompt a need for seed
bigroundofapplause
Clue
One might prompt a curtain call
huh
Clue
Answer that probably won't earn you any points on a game show unless the prompt is "This one-syllable sound usually indicates someone doesn't know what you're talking about"
Definition
used to express surprise
dulcimer
Clue
Musical instrument like a flat box, with a sounding box
Definition
a musical instrument like a flat box, with sounding board and wires stretched across bridges, also DULCIMORE
