To escape or get away from someone
Oh no, look over there, that's my old uncle. If we go for a greeting, we’ll be late. Let’s give him the slip! Let’s go that way.
Give somebody the slipinformal to escape from someone who is chasing you Somehow she’d given them the slip.
Cambridge Advanced Learner's Dictionary - 4th Edition
slip / slɪp / noun (ESCAPE)
give sb the slip informal
to escape from someone who is following or chasing you
© Cambridge University Press 2013
give sb the slip
If you give someone the slip, you escape from them when they are following you or watchingyou.
He gave reporters the slip by leaving at midnight.
give (someone) the slip
Definition of give (someone) the slip
: to escape (someone) : to get away from (someone)The robber gave the police the slip.