Answer: harped

AnswerCrossword Clue
HARPED

Dwelled

HARPED

Reiterated, with "on"

HARPED

Was a nag

HARPED
What the minstrel boy did.
HARPED
Dwelled (on)
HARPEDTalked nonstop on one subject
HARPEDTalked nonstop on a subject
HARPEDDwelled, with on