Migration Period spear

The spear or lance together with the sword, the longsax and the shield was the main equipment of the Germanic warriors during the Migration period and the Early Middle Ages.

Terminology
The pre-migration term reported by Tacitus is framea, who identifies it as "hasta";  The native term for "javelin, spear" was Old High German gêr, Old English gâr, Old Norse geirr, apparently from Proto-Germanic *gaizaz. The names Gaiseric, Radagaisus indicate Gothic gaisu besides gairu.

Latin gaesum, gaesus Greek γαῖσον was the term for the lance of the Gauls. Avestan has gaêçu "lance bearer" as a likely cognate. The Celtic word is found e.g. in the name of the Gaesatae. Old Irish has gae "spear". Proto-Germanic *gaizaz would derive from PIE *ghaisos, although loan from Celtic has also been considered, in which case the PIE form would be *gaisos. Pokorny has *g'haisos (with a palatal velar aspirate), discounting the Avestan form in favour of (tentatively) comparing Sanskrit  "projectile".

The form gaois is read in an early runic inscription on the so-called Mos spearhead, dated to the 3rd century, found in Stenkyrka, Gotland.

The etymon of English spear, from Germanic *speri (Old English spere, Old Frisian sper, Old High German sper, Old Norse spjör),  in origin also denoted a throwing spear or lance (hasta).

Ger
The word kêr or gêr is attested since the 8th century (Hildebrandslied 37, Heliand 3089).

Gar and cognates is a frequent element in Germanic names, male, Gary, Hrothgar, Holger, Oscar, Ansgar, Gernot, Rüdiger, Gerhart, Gerald, Gerben, female Gertrut, Gerlint and surnames Gehr, Gehrig, Gehringer.

Garseand survived in Southern France as Garçon to designate either all male youth, or a spear bearing arm.

The term survives into Modern German as Ger or Gehr (Grimm 1854) with a generalized meaning of "gusset" besides "spear". In contemporary German, the word is used exclusively in antiquated or poetic context, and a feminine Gehre is used in the sense of "gusset".

Framea
Tacitus (Germania 6) describes the equipment of the Germanic warrior as follows:
 * Even iron is not plentiful with them, as we infer from the character of their weapons. But few use swords or long lances. They carry a spear [hasta] (framea is their name for it), with a narrow and short head, but so sharp and easy to wield that the same weapon serves, according to circumstances, for close or distant conflict. As for the horse-soldier, he is satisfied with a shield and spear; the foot-soldiers also scatter showers of missiles each man having several and hurling them to an immense distance, and being naked or lightly clad with a little cloak. 

The term is also used by Eucherius, Gregory of Tours and Isidore. By the time of Isidore (7th century), framea referred to a sword, not a spear. Since Tacitus himself reports that the word is natively Germanic, various Germanic etymologies of a Proto-Germanic *framja, *framjō or similar have been suggested, but remain speculative. Must (1958) suggests *þramja, cognate to Old Norse þremjar "edges, sword blades", Old Saxon thrumi "point of a spear".

Anglo-Saxon gar rune
Gar "spear" is also the name of, a rune of the late Anglo-Saxon futhorc. It is not attested epigraphically, and first appears in 11th-century manuscript tradition. Phonetically, gar represents the /g/ sound. It is a modification of the plain gyfu rune.

Old English gâr means "spear", but the name of the rune likely echoes the rune names ger, ear, ior: due to palatalization in Old English, the original g rune (gyfu) could express either /j/ or /g/ (see yogh). The ger unambiguously expressed /j/, and the newly introduced gar rune had the purpose of unambiguously expressing /g/.

Gar is the 33rd and final rune in the row as given in Cotton Domitian A.ix.

Literature

 * Gustav Must, "The Origin of framea", Language, Vol. 34, No. 3 (Jul. - Sep., 1958), pp. 364–366.
 * Mark Harrison and Gerry Embleton, Osprey Warrior 005 - Anglo-Saxon Thegn 449-1066 AD