Compilers love HOMONYMS AND HOMOPHONES.

Sometimes a word has two or more distinct meanings. In fact, MEAN is a good example: ‘signify’, ‘ungenerous’ or ‘average’. A clue may be built round this: ‘Does it imply that you are tight-fisted?’ 

Some words sound the same but are spelt differently, such as ISLE and AISLE, and are generally indicated by something like ‘sounds like’ or ‘I hear’. Look at this one:

‘Part of the church which is surrounded by water, I hear’.  

An AISLE is part of a church, and it sounds like ISLE, which is of course surrounded by water.