1. in use - Phrase
2. in use - Adjective Satellite
(of facilities such as telephones or lavatories) unavailable for use by anyone else or indicating unavailability; (`engaged' is a British term for a busy telephone line)
currently being used
Source: WordNetThe logic now in use serves rather to fix and give stability to the errors which have their foundation in commonly received notions than to help the search for truth. So it does more harm than good. Francis Bacon
A nation or an individual, will do wisely to direct consumption chiefly to those articles, that are longest time in wearing out, and the most frequently in use. Jean-Baptiste Say
Just as iron rusts from disuse, and stagnant water putrefies, or when cold turns to ice, so our intellect wastes unless it is kept in use. Leonardo da Vinci
Apollo said that every one's true worship was that which he found in use in the place where he chanced to be. Michel de Montaigne
A man called, wanting to borrow a rope. "You cannot have it," said Nasrudin. "Why not?" "Because it is in use." "But I can see it just lying there, on the ground." Nasreddin
Hand in use is father of lair. Scottish Proverb