It sounds like you want to use a Criteria that looks like:
Like "*" & [Enter the word] & "*"
for that field. Your SQL would read:
select * from [Your Table]
where [Your Field] LIKE "*" & [Enter the word] & "*"
[Your Table] and [Your Field] you would have filled in. Assuming you want to
be prompted for the word or part of a word for which you want to search, the
[Enter the word] will open an input box to gather your word. If you only
ever want to search for the same word, then the word to search for is simply
hard coded: LIKE "*a Word*" or
select * from [Your Table]
where [Your Field] LIKE "*<whatever your word/partial word is>*"
(I enclosed the word in <...> to indicate that you would replace all of that
with the word that you were searching on.)
Good Luck!