A lift is musical; not lyrical. It channels the energy upward from the verse into the chorus.

When I teach my songwriting classes, this is what I use as a great example of a lift (or channel, or pre-chorus...all the same thing):

"You've Lost That Lovin' Feeling" (Mann, Weil)

VERSE
You never close your eyes any more when I kiss your lips
And there's no tenderness like before in your fingertips

LIFT
You're tying hard not to show it
But Baby, Baby, I know it...

CHORUS
You've lost that......etc

From the first note of the lift, it keeps going, up, up until it climaxes at the first note of the chorus.

Also, note how the first note of the chorus lands on the second count of the measure. The music allow that first chord to "land" hard (BOOM...you've lost that lovin...) before the singing starts. Brilliant.