Run smoothly, as an engine

This time we are looking on the crossword clue for: Run smoothly, as an engine.
it’s A 26 letters crossword puzzle definition. See the possibilities below.

Did you find what you needed?
We hope you did!. If you are still unsure with some definitions, don’t hesitate to search them here with our crossword solver.

Possible Answers: PURR, HUM.

Last seen on: –NY Times Crossword 22 May 23, Monday
LA Times Crossword 16 Nov 21, Tuesday
Newsday.com Crossword – Aug 26 2021
USA Today Crossword – Dec 14 2018