The difference between Couch and Lie down

Couch as a noun:

An item of furniture, often upholstered, for the comfortable seating of more than one person.

Couch as a noun:

A bed, a resting-place.

Couch as a noun (art, painting and gilding):

A preliminary layer, as of colour or size.

Couch as a noun (brewing):

A mass of steeped barley spread upon a floor to germinate, in malting; or the floor occupied by the barley.

Couch as a verb:

To lie down; to recline (upon a couch or other place of repose).

Couch as a verb (archaic):

To lie down for concealment; to conceal, to hide; to be concealed; to be included or involved darkly or secretly.

Couch as a verb:

To bend the body, as in reverence, pain, labor, etc.; to stoop; to crouch.

Couch as a verb (transitive):

To lay something upon a bed or other resting place.

Couch as a verb (transitive):

To arrange or dispose as if in a bed.

Couch as a verb (transitive):

To lay or deposit in a bed or layer; to bed.

Couch as a verb (transitive):

To lower (a spear or lance) to the position of attack.

Couch as a verb (ophthalmology, transitive):

In the treatment of a cataract in the eye, to displace the opaque lens with a sharp object such as a needle. The technique is regarded as largely obsolete.

Couch as a verb (paper-making, transitive):

To transfer (for example, sheets of partly dried pulp) from the wire mould to a felt blanket for further drying.

Couch as a verb (sewing, transitive):

To attach a thread onto with small stitches in order to add .

Couch as a verb:

To phrase in a particular style; to use specific wording for.

Couch as a noun:

, a species of persistent grass, Elymus repens, usually considered a weed.

Lie down as a verb (intransitive):

To assume a reclining position.

Lie down as a verb (intransitive):

To be lazy or remiss.

Lie down as a verb (intransitive):

To submit passively.