WordNet sense 1 (the area on a billiard table behind the balkline):

balk

WordNet sense 2 (something immaterial that interferes with or delays action or progress):

check, deterrent, handicap, hindrance, impediment, hinderance

WordNet sense 3 (one of several parallel sloping beams that support a roof):

rafter

WordNet sense 4 (refuse to comply):

jib, resist