Definition of "onely"

All flesh is grasse, is not onely metaphorically, but literally true, for all those creatures we behold, are but the hearbs of the field, digested into flesh in them, or more remotely carnified in our selves.

1643, Sir Thomas Browne, Religio Medici

on his right The radiant image of his Glory ſat, His onely Son;

1667, John Milton, “Book III”, in Paradise Lost. […], London: […] [Samuel Simmons], […]; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, lines 62–64

In which him chaunced false Duessa meete,Mine onely foe, mine onely deadly dread;Who with her witchcraft and misseeming sweete,Inveigled him to follow her desires unmeete.

1590, Edmund Spenser, The Faerie Queene