Khidmat is a Hindustani word.
A product of Ganga–Jamuni tehzeeb with roots in cultural syncretism. It is based on the premise of vasudhaiva kutumbakam (world is one family), unity in diversity and multi-communitarianism (individuals can practice more than one religious tradition).
In English it is 'service', in Hindi it is 'seva'. The use of Hindustani as a language is visible in the works of Amir Khusro and Munshi Premchand.