(architecture, uncountable) Areas of an architectural plan or section that are filled-in, often by cross-hatching or solid black, to show wall thicknesses, floor thicknesses and all other solid areas that intersect the plane of the section cut.
English Wiktionary. Available under CC-BY-SA license.
(2) As regards conjugation only two points need be noted here: (a) it employs the form known as the inchoative, that is to say, the lengthening of the radical of the present in verbs of the third conjugation by means of the syllable ex or ix, a proceeding common to Italian, Walachian, Provenal and French, but altogether unknown in Hispanic Romance; (b) the formation of a great number of past participles in which the termination is added; as in Provenal, not to the radical of the verb, but to that of the perfect: tingut from tinch, pogut from poch, conegut from conech, while in Castilian tenido (formerly also tenudo), podido, conocido, are participles formed from the infinitive.
As in Provenal, the past participle of a large ntimber of verbs of the 2nd and 3rd conjugations is formed, not from the infinitive, but from the perfect (pogut, volgut, tingut suggest the perfects poch, volch, tinch, and not the infinitives poder, voler, tenir).