lapse into
phrasal verb
lapsed into;
lapsing into;
lapses into
Definition of lapse into
1
: to begin using or doing (something that should be avoided) for a short period of time
He's a good writer, but he occasionally lapses into jargon.
2
: to begin to be in (a worse or less active state or condition)
The crowd lapsed into silence. The patient lapsed into a coma. The society lapsed into decline.