Probably a primary word (or perhaps a form of the article G3588); the relative (sometimes demonstrative) {pronoun} who6 {which} {what} that: - {one} ({an-} the) {other} {some} {that} {what} {which} who ({-m} {-se}) etc. See also G3757.
Verse
Matrix
Mat 11:17And saying, We have piped unto you, and ye haveG3738 not dancedG3738; we have mourned unto you, and ye have not lamented.
Mar 6:22And when the daughter of the said Herodias came in, and dancedG3738, and pleased Herod and them that sat with him, the king said unto the damsel, Ask of me whatsoever thou wilt, and I will give it thee.
Luk 7:32They are like unto children sitting in the marketplace, and calling one to another, and saying, We have piped unto you, and ye haveG3738 not dancedG3738; we have mourned to you, and ye have not wept.