nmod: nominal modifier
A nominal modifier. This is the label given to prepositional objects and other types of nominal dependents which are non-core arguments and not verbal modifiers (i.e. neither subject nor object nor oblique). Note that in keeping with Universal Dependencies for other languages, the nmod noun attaches directly to the lexeme it modifies (usually a noun), while the preposition is seen as a case dependent of the modifying noun.
ⲡ/DET ⲣⲏ/NOUN ϩⲛ/ADP ⲧ/DET ⲡⲉ/NOUN \n the sun in the sky
det(ⲣⲏ, ⲡ)
nmod(ⲣⲏ, ⲡⲉ)
case(ⲡⲉ, ϩⲛ)
det(ⲡⲉ, ⲧ)
Note that prepositional arguments of verbs are marked as obl, not nmod, including prepositional objects of verbs of perception:
ⲁⲣ/PRON ⲥⲱⲧⲙ/VERB ⲉⲣⲟ/ADP ⲓ/PRON \n You have heard me
nsubj(ⲥⲱⲧⲙ, ⲁⲣ)
obl(ⲥⲱⲧⲙ, ⲓ)
case(ⲉⲣⲟ, ⲓ)
nmod in other languages: [bej] [bg] [cop] [cs] [de] [el] [en] [et] [eu] [fi] [fr] [fro] [ga] [gd] [gsw] [gub] [hy] [it] [ja] [ka] [kk] [ky] [no] [pcm] [pt] [qpm] [ro] [ru] [sl] [ssp] [sv] [swl] [tr] [u] [xcl] [yue] [zh]