first-aider
He warned aiders of hooligans and criminals to desist from such acts.
Their names were added to a list of aiders of the enemy.
Some studies of home health aid staff showed that close relationships often developed between clients and aiders.

SMART Vocabulary: related words and phrases

Helpers and accomplices
a tower of strengthidiom
abettor
accessory
accomplice
acolyte
aide
backup
confederate
den mother
enabler
facilitator
father figure
partner
pinch hitter
right-hand man
room parent
sponsor
strength
support group
supporting cast