Each question gives a brief definition of a verb. The answer is also the name of a creature, so if the definition is 'To avoid being hit by crouching down', the answer is 'duck'. (Note: Only one word needed, i.e. 'duck' instead of 'to duck'.
-1.To attack vehemently. sea creature
-2.To brag. bird
-3.To track or trail persistently.
-4.To frighten with threats.
-5.To pinch on the buttocks. bird
6.To punch in the face.
-7.To bother constantly.
-8.To stretch, in order to get a better view. bird
-9.To close up tightly.
-10.To betray someone by giving information.