Meaning of “dip” - Learner’s Dictionary

dip

verb uk us /dɪp/ (present participle dipping, past tense and past participle dipped)
PUT INTO [ T ]

B2 to put something into a liquid for a short time:

She dipped the brush into the paint.
LOWER [ I ]

B2 to become lower in level or amount:

The number of students taking sciences has dipped sharply.

(Definition of “dip verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)