We all do it! Use vague language that is.
I just found myself writing an email in which I said ' We'll need an hour' for a meeting, and then I went back and changed it to 'We'll need an hour-ish'. This means that the reader can expect that the meeting might take a tad longer than an hour, rather than me intending to finish within the hour. The '-ish' tag makes the word a bit more vague. However, using -ish with a noun is not very common.
-ish is usually added to adjectives, like tall or short. Nice example at shortish - notice that the example is in the context of speech. -ish is not common in writing. More sentence examples of shortish - again these are all examples from speaking (both formal and informal), but should give you a reasonable idea of where and how you might use 'shortish'.
This Linguarama page gives examples of vague language in relation to time and so on . If you're interested in vague language generally, you might enjoy real examples of vague language in academia.
And how many examples of vague language can you notice in this blog?