disc▪ ṬRB_1 is only very scarcely attested in Sem (Ar and Jib; the Mand ‘cognate’ is probably an Arabism). Reconstruction difficult, etymology obscure. Any relation to ↗ḌRB ?
▪ ṬRB_2: According to some ClassAr dictionaries, there is no vb. corresponding to the n. maṭrab. Zabīdī, TA (as in Lane), however, mentions the expression ṭaribtu (or: ṭuribtu ?) ʕan al-ṭarīq ‘I deviated from the road, or way’. It seems natural to interpret this as *‘I was carried away (by a strong emotion)…’, in which case maṭrab could easily be seen as a n.loc. derived from ṬRB_1. – DRS nevertheless sets maṭrab apart as a value in its own right. If this should be justified, then maṭrab and ‘to deviate from one’s path’ are perhaps a reflexion of the vb. ‘to wander (from the road)’, vn. †ṭarb, that Ehret1989 considers to be an extension in »extendative *‑b «, from a 2-consonantal pre-protoSem base *ṬR- with the basic meaning of *‘to send’. For other such extensions, cf. ↗*ṬR-, ↗ṭaraʔa ‘to fall upon unexpectedly, happen, occur’, ↗ṭaraḥa ‘to remove, turn from, avert, throw far away’, ↗ṭarada ‘to push away, drive away, repel, expel, pursue, chase, drive together’.