adverb
: as one wishes : as or when it pleases or suits oneself
dreamer apparently moves about at will in the past, as well as in the present — Weston La Barre
blues sweep up from below, driving the school to the surface, there feeding upon them at will — L.K.Parritt
mounted … on bases that could be rotated at will — Military Review
: subject to one's discretion or pleasure : at one's disposal
where person enters land by permission of owner for an indefinite period, and without reservation of rent, he is tenant at will by implication — North Eastern Reporter