what can we say when somebody has taken a break from work
They have taken leave, annual leave, or a holiday.

If it is a longer break, they may have been allowed to take a sabbatical. This is a break of several months to around a year, usually unpaid, for people to go off and do something completely different - often travelling.
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If someone has taken an *** break from their work, we can also call it 'spending more time with their family'.

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That is what MP's always say when they have to leave office for some dubious reason!

Another one is 'garden leave'. If you have to hand in a notice period when you leave a job, but they don't want you there anymore, but refuse to let you move on to your new job before the notice period is up, you stay at home on 'garden leave'. (Doesn't sound too bad to me...)
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