[app. f. phrase top it (TOP v.1).] An attachment at the top of a boring rod by means of which it is withdrawn.
1839. Ure, Dict. Arts, 966. The boring tools … 13. The topit, or top-piece. Ibid. The runner, for taking hold of the topit.
1883. Gresley, Gloss. Coal Mining, Topit, a kind of bracehead, but much smaller, which is screwed on to the top of boring rods when withdrawing them from the hole. It is attached to a rope worked from a jack-roll.
