auxiliary
Pronunciation: /ɔːgˈzɪlɪəri, ɒg-/
adjective
noun ( plural auxiliaries)
- an auxiliary person or thing: a nursing auxiliary there are two main fuel tanks and two auxiliaries
- North American a group of volunteers giving supplementary support to an organization or institution: members of the Volunteer Fire Department’s women’s auxiliary
- Grammar an auxiliary verb.
- a naval vessel with a supporting role, not armed for combat.

Origin:
late Middle English: from Latin auxiliarius, from auxilium 'help'

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There is only one l in auxiliary.