Tinnimentum (tinnio) occurs only once, but from the context it plainly means a tinkling: illud quidem edepol tinnimentumst auribus, Rud. 806.
D. Abstract -mentum Words on Noun Stems
Of the two noun stem words in this class of abstract words, cognomentum is properly not a -mentum word. According to Lindsay (p. 335) the -to suffix is merely added to the -men suffix. An example is: meum cognomentum commemorat, M. G. 1038.
Lineamentum (linea) is seen from the following parallel examples to have the same meaning as its noun stem: in geometria lineamenta, formae, intervalla, magnitudines sunt, De Or. I, 187; ignis rectis lineis in caelestem locum subvolat, T. 1, 40; lineamentum esse longitudinem latitudine carentem, Ac. II, 116; eam M. Varro ita definit: linea est, inquit, longitudo quaedam sine latidudine et altitudine, Gell. 1, 20, 7.
This detailed view of the -mentum words gives occasion for making the following comment: the tendency of these nouns is to mean the instrument of an action, often the result of an action, rarely action itself. The verb stems are such as require an instrument for their action or suggest its result. The instrument is sometimes literal, sometimes figurative, and whether it is the one or the other is determined by the context. Given a verb stem which both suggests the result of action and requires an instrument, it is difficult to explain why a -mentum noun formed on it should mean only instrument, and not result of action, or vice versa.
II -BULUM
The list of -bulum words is small, and they are nearly all concrete. Only two are abstract. As these two denote only figurative instruments, the treatment here will take no account of the division into concrete and abstract. There are two noun stem words. Three distinct classes of these words may be made, when viewed in relation to their verb stems: (1) Those denoting instrument; (2) Those denoting place; (3) Those denoting person. The second meaning is quite as common as the first, the third very rare (found only in two nouns).
1. Nouns denoting instrument.
Patibulum (pateo) is plainly an instrument, but having the shape expressed by the verb stem, a fork-shaped yoke: dispessis manibus patibulum quom habebis, M. G. 360; caedes, patibula, ignes, cruces festinabant, Tac. A. 14, 33.
Rutabulum (ruo) is an instrument for raking or stirring up: iubebis rutabulo ligneo agitari quod decoxeris, Col. 12, 20. It occurs twice in Cato, in a list of other tools for use around a fire-place.