Ainu Morpheme Explorer
All place names

白老 しらおい Shiraoi

Shiraoi, Iburi region, Hokkaidō

Ainu spellings: Sirawoi, Sirawoy

The two readings share the ending o-i 'place where there are many' and differ in whether the first element is the horsefly or the ridge. The same question returns at Shirau in Biratori, where the author reads the name as a ridge name as well.

Location

42.5548, 141.3600 · Coordinates: OpenStreetMap Nominatim, 2026-09-10, on 白老. Open in OpenStreetMap

Referents

  • settlement The town of Shiraoi. Ainu settlement was heavy here from early times, and at the end of the Edo period the Sendai domain placed its eastern Ezo garrison camp there against Russia
  • river The Shiraoi River, whose three branches (Uyoro, Buubetsu and the Shiraoi proper) join at the coast into a single mouth; some old maps draw the three falling into the sea separately, while the Imai survey map already shows one mouth

Analyses

siraw-o-i

シラヲイ ‘place where there are horseflies’ received reading
  • siraw ‘horsefly’
  • o ‘have many of’
  • i ‘place’

Proponent: 定説

The received reading. An earlier river sign glossed it 'place of many rainbows', which the article puts down to the closeness of the characters 虹 and 虻. A survey reports Tabanus nipponicus in the Shiraoi valley in early August, so the insect is present.

Objections

  • A stream between Hidaka and Biratori is called Shirau on its own, so shiraw makes a place name by itself; an insect name alone is hard to accept as the source of one. — zenibako_trek zenibako_trek…
Confidence: low

siraw 'horsefly' is a dictionary word and the insect occurs in the valley; what the critique turns on is whether an insect name heads a place name of this shape.

zenibako_trek… 「白鵜(しらう)」zenibako_trek… 「白老(シラオイ)」

sir-aw-o-i

シラヲイ ‘place where ridge branches are many’ proposed
  • sir ‘mountain, ridge’
  • aw ‘branch’
  • o ‘have many of’
  • i ‘place’

Proponent: zenibako_trek(小樽銭函地名歴史研究会) (zenibako_trek (Otaru Zenibako Place-Name and History Society))

aw is used of a branch, as in pet-aw for the fork of a river. The name is read as describing the ground: several ridges run down toward the coast in the Shiraoi valley, hard to see on a map because they stop short of the sea but clear on a slope-gradient map. Records call these ridges Shiretoko, Shintoku, Eto or 'cape'; the old name of Hagino station was Shiretoko. The author reads the Shirau of Biratori the same way.

Confidence: low

sir is a dictionary word for land or mountain, while the sense 'branch' for aw is the author's: the Saru dialect dictionary gives aw as a root for a horn, for the inside of a house, for squid and for the neighbouring house. The landform the reading describes is documented in the names recorded for those ridges.

zenibako_trek… 「白老(シラオイ)」

Shira-o-i

‘The place where the tide comes out (over the land)’ proposed
  • Shira ‘tide’
  • o ‘come out’
  • i ‘place’

Proponent: John Batchelor

This well defines the locality for there are extraordinary high tides here on occasion.

Confidence: low

Batchelor's reading and gloss as printed in 1905; the segmentation is his, and several of its elements answer to no dictionary headword.

Batchelor1905 § V "Place Names Considered", s.v. Shiraoi

Related names

  • 虎杖浜・倶多楽湖 こじょうはま・くったらこ kuttar-us-i 'place where giant knotweed grows'. Kuttar is the knotweed and Kojōhama translates it into Japanese; the caldera lake inland carries the same name. The plant was of little use and often counted worthless. Kuttarushi names occur across Hokkaidō; Irifune in Otaru was one. zenibako_trek…
  • アフンルパロ ahun-ru-paro 'the mouth of the road into the other world', the cave beside Ayoro cape. Caves of that name are found all over Hokkaidō; oman-ru-paro is the same, since both ahun and oman mean to go in. The cave is shallow and ends soon, and only the dead are said to go further. At Omanrupar in Yoichi a man is said to have gone in after his lost wife. zenibako_trek…
  • ヨコスト yoko-us-to 'the marsh where one lies in wait for game'. The Yokosuto marsh spreads east of the town centre. zenibako_trek…
  • ポロトコタン poro-to 'big lake' plus kotan. Two lakes lie there, the larger poro-to and the smaller pon-to; Meiji-period maps call the present Poroto 'Ponto', so the name may have belonged to the smaller one. The settlement is a modern reconstruction, not an old kotan. The Sendai domain map draws the lake water joining the Shiraoi River. zenibako_trek…

Sources

zenibako_trek… zenibako_trek… Batchelor1905