If a termagant were a hybrid of the tern and the cormorant (both seabirds), you might be on the right track. However, a termagant
is a boisterous, quarrelsome, scolding woman. She would likely berate you repeatedly for not knowing that termagant is a synonym for shrew.
In Vanity Fair, shy and sweet Amelia learns that her soldier husband is about to be transferred out of England to Belgium and insists on accompanying him:
"I must and will go," Amelia cried with the greatest spirit; and George, applauding her resolution, patted her under the chin, and asked all the persons present if they ever saw such a termagant of a wife, and agreed that the lady should bear him company.