Lewis & Short

laxĭtas, ātis, f. [laxus], width, roominess, spaciousness, extent.

  1. I. Lit. (rare but class.), of a house, Cic. Off. 1, 39, 139: loci, Sall. ap. Non. 132, 23: laxitas appellatur Propontis, angustiae Thracius Bosporus, the wide part, Plin. 4, 12, 24, § 76: mundi, id. 14 prooem. § 5: spatiosa, id. 8, 43, 68, § 169: hae semitae opportunam laxitatem praebent, Col. 4, 18: aëris. i. e. a free current of air, Pall. 1, 5.
  2. * II. Trop., laxity, languor, Arn. 6, 197.