quick‧en [intransitive and transitive]
to become quicker or make something quicker:
Ray glanced at his watch and quickened his pace (=began to walk faster).
Companies are finding it hard to cope with the quickening pace of technological change.
your heart/pulse/breathing quickens (=your heart beats faster because you are afraid, excited etc)
She caught sight of Rob and felt her heart quicken.
if a feeling quickens, or if something quickens it, it becomes stronger or more active [= increase]:
This policy served only to quicken anti-government feeling.