prefix of ''altercation''

The prefix of the word ''altercation'' is "alter". Prefix means a letter or group of letters added to the beginning of a word to change its meaning, such as un- in unhappy

In the word 'altercation', 'alter' is not its prefix. The word 'altercation' has no prefix. The word does not have the structure of prefix + root word or prefix + root word + suffix.
''alter' is a Latin base word here. Pls check the website for reference:

http://www.palosverdes.com/jesse/pvphs/www-freecollege-com-vocab.htm
4. Latin Base WordsLatin wordMeaningExamples

alter, ALTERother, anotheralternative, altercation, ADULTERATE