Translingual

Symbol

Ps

1. (physics) positronium
2. (metrology) Symbol for the petasecond, an SI unit of time equal to 10¹⁵ seconds.

English

Noun

Ps

1. plural of P

Usage notes

• There is some difference of opinion regarding the use of apostrophes in the pluralization of references to letters as symbols. New Fowler's Modern English Usage, after noting that the usage has changed, states on page 602 that "after letters an apostrophe is obligatory." The 15th edition of The Chicago Manual of Style states in paragraph 7.16, "To avoid confusion, lowercase letters ... form the plural with an apostrophe and an s". The Oxford Style Manual on page 116 advocates the use of common sense.

German

Alternative forms

• Ps.

Noun

Ps

1. (abbreviation of Psalm(en)) Psalm(s)/psalm(s)

Translingual

Symbol

ps

1. (metrology) Symbol for the picosecond, an SI unit of time equal to 10⁻¹² seconds.

English

Noun

ps

1. plural of p

Usage notes

• There is some difference of opinion regarding the use of apostrophes in the pluralization of references to letters as symbols. New Fowler's Modern English Usage, after noting that the usage has changed, states on page 602 that "after letters an apostrophe is obligatory." The 15th edition of The Chicago Manual of Style states in paragraph 7.16, "To avoid confusion, lowercase letters ... form the plural with an apostrophe and an s". The Oxford Style Manual on page 116 advocates the use of common sense.

Initialism

ps

1. Alternative form of PS (post scriptum).