An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The act of adopting. The state of being adopted.

→ adopt; → -tion.

1) The power or right of choosing.
2) Something that may be or is chosen; choice.
3) The act of choosing (Dictionary.com).

→ opt; → -tion.

Left to one's choice; not required or mandatory (Dictionary.com).

→ option; → -al.