Definition: The position of an individual in relation to another or others, especially in regard to social or professional standing. It refers to relationship type: friend, relative, acquintance, co-worker.

Is this for a job reference? If so, it is likely that the form is looking for the relationship between that person and you - for example, "Former employer" or "University Tutor" (feel free to send me a personal message if you want me to look at the whole form, it doesn't sound very clear)