lumectum

From lūma (“thorn”) +‎ -tum. The -ec- appears to be by analogy to forms like frutectum (“thicket, bush”), cārectum (“reed bed”).

• (Classical Latin) IPA^(key): [ɫuːˈmɛk.tũː]
• (modern Italianate Ecclesiastical) IPA^(key): [luˈmɛk.t̪um]

lūmectum n (genitive lūmectī); second declension

1. a thicket of thorns

Second-declension noun (neuter).

• “lumectum”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• lumectum in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.