tignum：建筑材料，是拉丁语，太正式，确实一般词典都查不到
此处我帮你查到的意思如下：
tignum：[ ?tign?m ]建筑材料；木屋顶的系梁。 [生物学] 殖弧梁；
它的衍生词, 相关词
tignum → construction train, strength timber, CBMM, glassteel, glulam, pise, formwork, building paper, building trade
在Wiktionary维基百科里找到的tignum的详细注解如下：
tignum (genitive tignī); n, second declension
Latin
Noun
tignum (genitive tignī); n, second declension
1.tree trunk
2.log
3.beam
Inflection
Number Singular Plural
nominative tignum tigna
genitive tignī tignōrum
dative tignō tignīs
accusative tignum tigna
ablative tignō tignīs
vocative tignum tigna
希望能帮到你。