By equal alternating periods of service or duty; by turns.

simple past tense and past participle of turn

Third-person singular simple present indicative form of turn

plural of turn

plural of turning

simple past tense and past participle of turn into

Third-person singular simple present indicative form of turn into

One after the other; successively; alternating. / (obsolete) At intervals; from time to time.

Third-person singular simple present indicative form of turn on

simple past tense and past participle of turn on