Underpants – le slip
(Pronounced sleep)
To remember that Underpants is pronounced sleep (slip) in French, use the following mnemonic:
Why were her underpants on her head when she went to sleep (slip)?

Slip is masculine, so it's le slip. Imagine the early learner using massive underpants as a parachute.

Examples of slip (underpants) in a sentence
Je me suis retrouvé en slip
(I found myself in my underwear.)
J'ai mis mon slip à l'envers ce matin.
(I put my underpants on inside out this morning).
Il n'est pas assis sur ton canapé en slip.
(He isn't sitting on your couch in his underwear).