fälla in

Verb

 * 1)  (when an inward motion in some sense)
 * 2) to retract, etc. (when more idiomatic)
 * 1) to retract, etc. (when more idiomatic)
 * 1) to retract, etc. (when more idiomatic)
 * 1) to retract, etc. (when more idiomatic)

Usage notes
Might rarely instead mean the opposite, if the "open/activated" position of something is in.