did, bed, head, it: DEAD
flat, lack, lap, Latin: BLACK
trauma, job, chalk, drama: JAVA
nor, more, Mark, your: NORTH
mentoring, meditating, nutrient, mainframe:
MEDITERRANEAN
faulted, vaulted, phobic, bulk: BALTIC
sarcasm, sarcastic, surpass, sergeants: SARGASSO
asking, casting, caffeine, napkin: CASPIAN
jibe, Hannah, chat, shined: CHINA
quarrel, oral, call, full: CORAL
The final answer is SEA.