The difference between Manual and Semi-automatic

When used as nouns, manual means a handbook, whereas semi-automatic means a semi-automatic firearm, especially such a pistol.

When used as adjectives, manual means performed with the hands (of an activity), whereas semi-automatic means partially automatic.

check bellow for the other definitions of Manual and Semi-automatic

Manual as a noun:

A handbook.
Manual as a noun:

A booklet that instructs on the usage of a particular machine or product.

Examples:

"The dishwasher isn't working; can you remember where we put the manual?"
Manual as a noun (military):

A drill in the use of weapons, etc.
Manual as a noun (Christianity, historical):

An old office-book like the modern Roman Catholic ritual.
Manual as a noun (music):

A keyboard for the hands on a harpsichord, organ, or other musical instrument.
Manual as a noun:

A manual transmission; a gearbox, especially of a motorized vehicle, shifted by the operator.
Manual as a noun (by synecdoche):

A vehicle with a manual transmission.
Manual as a noun:

A bicycle technique whereby the front wheel is held aloft by the rider, without the use of pedal force.
Manual as a noun (medicine, colloquial):

Manual measurement of the blood pressure, done with a manual sphygmomanometer.

Examples:

"do a manual"

Manual as an adjective:

Performed with the hands (of an activity).
Manual as an adjective:

Operated by means of the hands (of a machine, device etc.).
Manual as an adjective (technology):

Performed by a human rather than a machine.

Examples:

"The student manually corrected several errors missed by the [[spell checker]]."

Semi-automatic as an adjective:

Partially automatic.
Semi-automatic as an adjective:

Of a firearm that automatically ejects a shell and loads the next one, but requires the trigger to be squeezed for each shot; autoloading.

Semi-automatic as a noun (weapons):

A semi-automatic firearm, especially such a pistol.
Semi-automatic as a noun (automotive):

A semi-automatic transmission