| double(noun, adjective, cover, substitute, joint) |
| every other(expression, adjective, idiom, irregular, infrequent) |
| temporary(adjective, present, short, substitute, replacement) |
| alternating(adjective, irregular, erratic, other, recurrent) |
| fill-in(noun, adjective, person, informal, copy) |
| rotate(verb, change, interchange, forth) |
| sub(noun, adjective, person, cover, informal) |
| waver(verb, change, alter, pause, swing) |
| delegate(noun, supply, agent, replacement, representative) |
| equivalent(noun, adjective, substitute, replacement, backup) |
| makeshift(adjective, limited, substitute, brief, replacement) |
| seesaw(verb, stop, change, alter, shift) |
| take turns(verb, expression, idiom) |
| intermittent(adjective, irregular, other, sporadic, discontinuity) |
| reciprocate(verb, change, shift, reverse, trade) |
| recurrent(adjective, other, discontinuity, regularity of recurrence periodicity, repeating) |
| representative(noun, extra, agent, substitute, replacement) |
| flip-flop(verb, change, shift, reverse, trade) |
| hesitate(verb, change, alter, pause, swing) |
| periodic(adjective, other, discontinuity, regularity of recurrence periodicity) |