1.
indisposed to action or exertion; lacking in energy; lazy; indolent:
a sluggish disposition.
2.
not acting or working with full vigor, as bodily organs:
a sluggish liver.
3.
slow to act or respond:
a sluggish car engine.
4.
moving slowly, or having little motion, as a stream.
5.
slow, as motion.
6.
slack, as trade, business, or sales.