To squirrel something away means to hide or save something to use it in the future.
Joan's salary is very low but a few years ago she started to squirrel money away. It took her a long time, but she finally saved enough for a deposit for a flat.
Just how much personal information are websites squirrelling away about us from our own computers?
Don't confuse with the phrase to weasel out. If you say somebody weaselled out of something you mean they avoided doing a job or taking responsibility for something.
Mary wanted a promotion but didn't want to work hard so she tried to weasel her way out of the most difficult tasks in the office.
Householders in Britain whose bird tables are a target for hungry squirrels are being encouraged to add a bit of spice to the meal. The UK's Royal Society for Protection of Birds said chilli powder is a safe and effective way to keep squirrels away from nuts and seeds, without harming garden birds.