Joker
Truncation

Truncation is like a wildcard. Added to the stem of a word, it will find that stem plus anything that comes after it. The symbol used to truncate a word depends upon the index, database, or Web search engine you are using.

psychol$ will return records on psychology, psychological, psychologist.
$ is used as the truncation symbol, for example, in the Library Catalog.
environ* will return records on environment, environments, environmental.
* is used as the truncation symbol in EBSCOhost and ProQuest databases.
acqui! will return records on acquistions, acquisitioning, acquires and acquiring.  ! is used as the truncation symbol in Lexis-Nexis Academic.
wom?n will return records on woman and women.  In most databases, the ? symbol is used to handle variant spellings within words. 
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