Etymology: Origin uncertain; perhaps < Dutch haperen to stutter, stammer (c1350 in Middle Dutch, now usually in the sense ‘to falter, hesitate’), of uncertain origin; perhaps a frequentative formation (compare -er suffix⁵) < Dutch happen seize, grab, grasp with mouth (see hap v.³), although this does not appear to be attested until later than the frequentative verb in Dutch (1588). Compare German hapern (17th cent.), Swedish hapra (1683), happla (1710), all in sense ‘to stutter’.

Etymology: Origin uncertain; perhaps a frequentative formation (compare -er suffix⁵) ultimately from a base imitative of a light tapping sound (compare e.g. tap v.², rap v.², pat v.¹, and also patter v.²), although with sense 1 perhaps compare hop v.¹ and variants at that entry, and also Middle Dutch, Dutch huppen to hop, jump (see hip v.¹ and forms from Germanic languages cited at that entry), early modern Dutch hupper, hipper locust (1588 in Kiliaan, or earlier).