shift

Just last week she bought a new shift at the market.

We'll work three shifts a day till the job's done.

There was a shift in the political atmosphere.

Does it come with a stick-shift?

If you press shift-P, the preview display will change.

Teams often use a shift against this lefty.

If I get down, and do not break my limbs,

I'll find a thousand shifts to get away:

As good to die and go, as die and stay.

And if the boy have not a woman's gift

To rain a shower of commanded tears,

An onion will do well for such a shift

This kind of change, called shift - or more memorably, 'viral sex' - tends to trigger a pandemic, because a radically different virus demands a radically different immune response, and that takes time to mobilise.