Thread
A thread was a type of fiber used in fabric sewing and suturing.
In 2375, while berating Chakotay for abusing his body by boxing, The Doctor quipped that he ought to use a needle and thread to stitch his wounds for good measure. Chakotay invited him to do so, and The Doctor replied, "You'd like that. A manly scar above your eye." (VOY: "The Fight")