Definitions of reflection:

• noun:   the image of something as reflected by a mirror (or other reflective material)

  Example: "He studied his reflection in the mirror"

• noun:   the ability to reflect beams or rays
• noun:   the phenomenon of a propagating wave (light or sound) being thrown back from a surface
• noun:   (mathematics) a transformation in which the direction of one axis is reversed
• noun:   a likeness in which left and right are reversed
• noun:   a calm lengthy intent consideration
• noun:   a remark expressing careful consideration
• noun:   expression without words

  Example: "The pulse is a reflection of the heart's condition"