'associability' is formed in Modern English from the verb 'associate' plus the noun-forming suffix '-ability'. 'Associate' ultimately comes from Latin 'associare' (or past participle 'associatus'), where the prefix 'ad-' (becoming 'as-') meant 'to, toward' and 'socius' meant 'companion, ally'.

'associate' came into English via Latin 'associare' and Old/Middle French forms such as 'associer'; the modern noun 'associability' was built later in English by adding the suffix '-ability' (from Latin '-abilitas') to express the capacity to be associated.

Originally related to the action of joining or uniting with others ('to join, unite with'), the term evolved into a noun expressing the general capacity or quality of being able to form associations or be linked ('capacity to be associated').