Rayner, Rainer, Rainier

Gender: Masculine
Origin: German
Meaning: “army advice.”

The name is the English form of the Old Germanic, Raganhar, which is composed of the elements, ragin, meaning “advice” and har, meaning “army.”

The name was introduced into England via the Normans and subsequently fell out of usage by the High Middle Ages.

Other forms of the name include:

Ragnar (Danish/Estonian/Icelandic/Norwegian/Swedish)
Regner (Danish)
Reinier (Dutch)
Rain (Estonian)
Raino (Estonian/Finnish)
Rauno (Estonian/Finnish)
Raknar/Raknari/Raknu (Finnish)
Rainier (French)
Rainer/Reiner (German/Estonian)
Nero (Italian)
Raniero (Italian)
Riniero (Italian)
Neer (Limburgish)
Reneer (Limburgish)
Ragnarr (Old Norse)
Rajner (Polish)
Rávdnár (Sami)
Rainerio (Spanish)

Nicknames include:

Rein (Dutch)
Raik and Reik (German)
Ranuccio, Nero (Italian)
Ragge (Swedish)

Feminine forms are:

Raina (German/Estonian)
Raniera/Rainera (Italian)

The name is a common one in the Grimaldi house of Monaco, it was borne by Prince Rainier I Grimaldi (1267-1314); Rainier II Grimaldi (1350-1407) and the late Prince of Monaco, Prince Rainier III (1923-2005)

The designated name-day is October 1 (Estonia/Finland/Sweden).

Source

1. http://www.behindthename.com/php/find.php?name=ragnar