[op.tion.al] adj (1792): involving an option: not compulsory -- op.tion.al.i.ty n -- op.tion.al.ly adv
OPTIONAL
Meaning of OPTIONAL in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012
[op.tion.al] adj (1792): involving an option: not compulsory -- op.tion.al.i.ty n -- op.tion.al.ly adv
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012