Thesaurus.com
Dictionary.com
Definitions

thread

[thred] / θrɛd /
NOUN
a fine strand of twisted fibers
Synonyms
STRONGEST
cord cotton fiber filament hair ribbon strand string wire wool yarn
STRONG
braid fibril floss gossamer lisle
NOUN
fiber
Synonyms
STRONGEST
cord cotton filament silk strand string wire wool yarn
STRONG
flax floss ligature lint lisle pile ravel raveling stamen staple thrum twine warp weft woof

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.