Both Uses of

loath

in

The Tempest

You were kneel'd to, and importun'd otherwise By all of us; and the fair soul herself Weigh'd between loathness and obedience at Which end o' th' beam should bow.†
Scene 2.1 *

loathness = the quality of being highly reluctant or unwilling

Then, as my gift and thine own acquisition Worthily purchas'd, take my daughter: but If thou dost break her virgin knot before All sanctimonious ceremonies may With full and holy rite be minister'd, No sweet aspersion shall the heavens let fall To make this contract grow; but barren hate, Sour-ey'd disdain, and discord, shall bestrew The union of your bed with weeds so loathly That you shall hate it both: therefore take heed, As Hymen's lamps shall light you.†
Scene 4.1

Definitions:

(1) (loath)
reluctant or unwilling to do something

Word Confusion: Do not confuse loath with loathe which sounds very similar or the same. Loath is typically used as an adjective while loathe is a verb that means "to dislike greatly".
(2) (meaning too rare to warrant focus)