swear by something phrasal verb informal ( see also ↑ swear )
to have great confidence in how good or effective something is:
He swears by vitamin C pills.
swear by something phrasal verb informal ( see also ↑ swear )
to have great confidence in how good or effective something is:
He swears by vitamin C pills.
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012