Defn: The property possessed by living protoplasm of contracting, and thus moving, when touched by a solid or fluid substance.

When the movement is away from the touching body, it is negative
thigmotaxis; when towards it, positive thigmotaxis.

THILK
Thilk, pron. Etym: [Cf. Ilk same.]

Defn: That same; this; that. [Obs.] "I love thilk lass." Spenser.
Thou spake right now of thilke traitor death. Chaucer.

THILL Thill, n. Etym: [OE. thille, AS. a board, plank, beam, thill; akin to a plank, D. deel a plank, floor, G. diele, OHG. dili, dilla, Icel. a plank, planking, a thwart, a wainscot, plank; cf. Skr. tala a level surface. *236. Cf. Fill a thill, Deal a plank.]

1. One of the two long pieces of wood, extending before a vehicle, between which a horse is hitched; a shaft.

2. (Mining)

Defn: The floor of a coal mine. Raymond. Thill coupling, a device for connecting the thill of a vehicle to the axle.

THILLER
Thill"er, n.

Defn: The horse which goes between the thills, or shafts, and supports them; also, the last horse in a team; — called also thill horse.