Weaving machine may appear menacing
I believe the answer is:
loom
I believe this is a double definition.
'weaving machine' is the first definition.
(machine for weaving thread)
'appear menacing' is the second definition.
(I've seen this in another clue)
'may' acts as a link.
(Other definitions for loom that I've seen before include "Appear large and indistinct, to weave?" , "See 12" , "Textile machine for weaving" , "Appear indistinctly, in threatening form" , "Of future event, seem ominously close" .)