A Squish is a platonic crush, where one strongly desires to be close to a particular individual, but not in a romantic way. It is common for aromantic and other a-spec individuals to experience squishes, though it is not exclusive to them, and not all a-spec individuals experience squishes. It is defined as the desire to be close friends with a particular individual, or to become closer friends with a particular individual if one is already friends with them. It may also be used for a desire to be in a queerplatonic relationship with a particular individual, or as any sort of crush that is not romantic or sexual in nature.
A squish can possibly include thinking about the individual in question, enjoying being around them, getting flustered around them, wanting the individual to consider oneself a friend or a best friend, and possibly a desire physical closeness with them. However, one does not consider their squish as a romantic partner or potential romantic partner. Any form of emotional connection or physical closeness is not considered to be romantic in nature by the individual with the squish.
Having squishes is not the same as a general "desire for friends". A squish is targeted towards a specific individual. One can desire friends without feeling squishes. Someone who does not experience squishes may call themself aplatonic.