retreat phoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticphonetic verb [I] 
to go away from a person or place, esp. because unwilling to fight any more; to withdraw 
Attacks by enemy aircraft forced the tanks to retreat (from the city).
When she came towards me shouting, I retreated (behind my desk).
FIGURATIVE I retreated to a place in the mountains to put my thoughts on paper.
FIGURATIVE When he's afraid he retreats under the blankets/to his bedroom/into himself/into a fantasy world.
FIGURATIVE The government is retreating from (=failing to keep to) its principles/beliefs/promises.

retreat phoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticphonetic noun 
Thousands of soldiers died on the retreat. [C]
FIGURATIVE The professor's speech marked/signalled a retreat from his usual extreme views. [C]
Enemy soldiers are now in (full) retreat. [U]

A retreat is also a private and safe place. 
Mike has a small comfortable retreat by the lake.
They have long used the flat as an invaluable retreat from the bustle of the school. students extra lessons out of school.

A retreat is also a period of time used to pray, study, or think carefully. 
We went on a retreat at a monastery.
( Cambridge International Dictionary of English )