Answer: sacroiliac

AnswerCrossword Clue
SACROILIACJoint at the base of the spine
SACROILIACStrong pelvic joint
sacroiliacRelating to the sacrum and the ilium
sacroiliacDenoting the rigid joint at the back of the pelvis between the sacrum and the ilium
sacroiliacrelating to the articulation of the sacrum and ilium / the joint that articulates the sacrum and ilium