2. A-bomb
noun. a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium 235 or plutonium 239).
Synonyms
Antonyms
3. A
noun. a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation.
5. A
noun. the basic unit of electric current adopted under the Systeme International d'Unites.
Synonyms
6. A
noun. one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose).
Synonyms
7. a
noun. ['ə, ˈeɪ'] the 1st letter of the Roman alphabet.
Etymology
- a (Middle English (1100-1500))