Lewis & Short

tīrōcĭnĭum, ii, n. [tiro].

  1. I. Lit.
    1. A. In milit. lang., the first military service or first campaign of a young soldier, military rawness or inexperience, = rudimentum (perh. not ante-Aug.): juvenis, Liv. 39, 47, 3: propter exercitūs paucitatem et tirocinium, Auct. B. Afr. 31, 6: aetatis infirmitas aut militiae tirocinium, Val. Max. 5, 4, 2: tirocinii rudimenta deponere, Just. 9, 1, 8.
      In plur.: si non solum tirocinia, verum et incunabula in ipsis castris posuissent, Just. 12, 4, 6; Flor. 2, 3.
    2. B. Concr., the young troops, raw forces, recruits: contemptum tirocinium, Liv. 40, 35, 12.
  2. II. Transf., in gen., the first beginning of any thing, the first trial, attempt, or essay: si in L. Paulo accusando tirocinium ponere et documentum eloquentiae dare voluit, Liv. 45, 37, 3 Weissenb. ad loc.; cf.: nec differendum est tirocinium in senectutem, Quint. 12, 6, 3; and: tirocinii metum transire, id. 12, 6, 7: filios suo quemque tirocinio deducere in forum, i. e. after putting on the toga virilis, Suet. Aug. 26: dies tirocinii, id. Tib. 54: togam sumpsit barbamque posuit, sine ullo honore, qualis contigerat tirocinio fratrum ejus, id. Calig. 10.
    Of inanim. things: navium, i. e. their first voyage, Plin. 24, 7, 26, § 41.
    1. B. Inexperience: senatus cum simul et tirocinio et perturbatione juvenis moveretur, Liv. 39, 47, 3: nec tirocinio peccet, Manil. 1, 189.