head for the hills vs turn tail

head for the hills and turn tail both are verbs.

Word	Noun	Adjective	Verb	Adverb
head for the hills	No	No	Yes	No
turn tail	No	No	Yes	No

As verbs, head for the hills and turn tail are synonyms defined as:

head for the hills and turn tail: flee; take to one's heels; cut and run

Other synonyms of head for the hills include break away, bunk, escape, fly the coop, hightail it, lam, run, run away, scarper, scat, take to the woods.

head for the hills (verb)	turn tail (verb)
flee; take to one's heels; cut and run	flee; take to one's heels; cut and run