Forming a necessary part, base, or core. (Music) the lowest note in a harmony.

To offer or give something that is wanted, needed.

particle representing quantum of light or other electromagnetic radiation. Quantum of electromagnetic radiation.

effort to achieve something. To try to do something challenging or difficult.

Larger in size or number.

An advantage. consider or regard.

of no value. not at all. Item of little or no value, importance, interest. not anything.

discrete quantity of energy proportional in magnitude to frequency of radiation.

reflective surface. Things with glass surface used to look at yourself. To have similar qualities to something else.

Very big; large; too big.

of nature of copy. close or exact copy. To make one or more exact copies of itself.

(of shooting) carried out to protect exposed person from enemy. thing used to protect, decorate, or conceal something else. (Police or military) to protect from attack.

act in such way as to have effect on each other.

officially compulsory, or otherwise considered essential. To need something, to make it necessary.

spread throughout.