The phrase "a certain retreat" is correct and usable in written English.
It can be used when referring to a specific but unspecified retreat, often implying a place of rest or a withdrawal from a situation.
Example: "After a long week, I decided to visit a certain retreat in the mountains to recharge."
Alternatives: "a particular retreat" or "a specific retreat".
Today I co-facilitate with Jana for the retreats that donate a portion of all proceeds to domestic violence and child abuse causes and gift a certain number of retreat seats to women in shelters.
They are capable of taking the lead with good, forceful attacking but if the cushion of a second goal has not arrived by a certain point, West Ham retreat and invite pressure.
You might find yourself giving in to what people want to a certain extent, and then retreating or resisting their attempts to control you.
She was serious and she wants Andrea to pull her weight; certain people are stuck with certain tasks and to a certain extent people are retreating back into traditional gender roles because of how this survival-crazy world seems to work.
He was already watching for signs of retreat: impatience, condescension, a certain weariness.
You fight him in stages across the length of the game's final level, with the boss retreating automatically once a certain level of damage is inflicted.
From a certain point of view, going on an intensive meditation retreat is a radical thing to do.
Most enemies will attack the player on sight, retreating in terror if they reach a certain threshold of damage without being killed.
As examples, patients may reschedule at the time of treatment and thus be retreated based on a fixed time, regardless of need; they may choose to be retreated before return to baseline to maintain a certain level of improvement in appearance.
Self-assessment can occur during a contest, when an individual will decide to retreat when the costs inflicted by the opponent reaches a certain threshold [1], [24].
