Answer: shallowest

AnswerCrossword Clue
shallowest(of breathing) Taking in little air
shallowestSituated at no great depth
shallowestNot exhibiting, requiring, or capable of serious thought
shallowestSHALLOW, having little depth
shallowestVarying only slightly from a specified or understood line or direction, esp. the horizontal
shallowestOf little depth