IPA: /əˈsaɪnər/
KK: /əˈsaɪnər/
A person or thing that gives out tasks or responsibilities to others.
The assigner distributed the projects among the team members.
Assigners are formed from 'assign' (from Latin 'assignare', meaning to allocate or designate) and '-er' (meaning a person who). An assigner is a person who allocates or designates tasks or responsibilities.
Think of someone who 'designates' ('assign') tasks — the '-er' just means a person. An assigner is someone who allocates responsibilities.