slip in

slip in

1. To place, insert, or load someone or something inside of something else. In this usage, a noun or pronoun can be used between "slip" and "in." Go up to their mailbox and slip in this letter. He slipped a new magazine in and cocked the rifle.
2. To enter (something or some place) quickly, easily, or inconspicuously. The teacher had already started his roll call, but Josh managed to slip in without him noticing. I hate trying to slip in my sleeping bag without waking other people.
See also: slip
Farlex Dictionary of Idioms.

slip something in (to) something

 and slip something in
to cause something to slide or glide into something. Max slipped the bullets into their chambers and got ready to fire. He slipped the bullets in silently.
See also: slip

slip in

(some place) to sneak or go into a place quietly and unnoticed. I think we can slip in the rear door unnoticed. We slipped in and crept up the stairs.
See also: slip

slip in(to something)

to slide or glide into something, such as clothing, a sleeping bag, a tight place, etc. I don't want to slip into a cold sleeping bag. How can I warm it up? I opened the bag and slipped in.
See also: slip
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

slip in

v.
1. To insert something gradually, easily, or without being noticed: She took a dollar bill and slipped it in the birthday card. He slipped in a comment during their conversation.
2. To enter gradually, easily, or without being noticed: The party had already started, so I slipped in and got a drink. The thief slipped in the back door.
See also: slip
The American Heritage® Dictionary of Phrasal Verbs.
See also:
  • add in
  • (someone or something) promises well
  • all right
  • a/the feel of (something)
  • (I) wouldn't (do something) if I were you
  • (have) got something going (with someone)
  • a straw will show which way the wind blows
  • accompanied by
  • accompanied by (someone or something)
  • accompany