Outbuilding, storehouse, granary, after the granaries dating back to the 17th C at least. See, for example, the one converted into the present-day Estonian Museum of Applied Art and Design on the corner of Lai, or the Olde Hansa on Vana Turg. Prior to this, known as Speichergasse or ‑straße [Ger.] or Амбарный пер, etc. [Ru.] (warehouse/barn alley), Kleine Klosterstraße (Lesser Convent St) until sometime around the 18th C and at one time simply põiktänav kloostri müüri ääres (± ‘side road running along the cloister walls’, in TT but not KNAB).
Chemist’s, pharmacy, apothecary’s. Named after Tallinn’s oldest, the nearby Raeapteegi mentioned as far back as 1422. Apteegi as street name was first given in municipal records of 1611 as Apoteker Gasse, with later (1614) marginalia alters die Lütke Schröder Strasse (formerly the Little Tailor’s street). Prior to this (1389), the street was known/described as parva platea sartorum, qua itur de foro ad monachos (little road of the ‘tailors’ [see below], which goes from the market to the monks, i.e., today, to Vene), and before that (1368) platea monachorum, road of the monks, these being the Dominican Friars (see Dominiiklaste). Note on tailors... the Latin sartor indicates someone who repairs, and stitching wounds to Saville Row is as far as barbers to surgeons (cf. the red and white spiraled barber’s pole: red for blood-letting and white for bandages). So the street probably specialized in buttons and bones, leeches and breeches. Makes you glad to live in the 21st‑C.
Exchange, stock exchange. Once known by the name of Kilstoa kangialune or guildhall archway. German Börse (stock exchange > purse), French bourse and English purse share the same etymology, from Greek βύρσα, hide, leather, through low Latin bursa, small bag with drawstrings (hence expression ‘to purse one’s lips’) in which money was kept, to modern-day purse and stock exchange. The story of a 14th‑C Bruges family, van de Borse or Van Der Burse, at whose house local and Venetian merchants used to meet and do business may well be apocryphal or incidental. Popular French etymology has often suggested that the bourse was kept against the groin, a site of great physical sensitivity and awareness and, true to form, one of the earliest uses (1278) of the term bourse (Mod. Fr. les bourses) was scrotum. And where better to keep a bag containing your valuables than next to another bag containing your valuables?
Although Dunker is an old Germanic name for someone who lived near a swamp – historically, pretty much applicable to anyone in Estonia – it seems this was a 16th‑C merchant, originally from Lübeck, prime city of the Hanseatic League, as well as Tafelbruder (see Eppingi torn) and/or alderman. Having been the street’s name for the past 400-odd years, it has inevitably been wrangled into cosier interpretations: Drunckerstraße (1528), possibly, but not 100% sure, ‘drunkard’s street’, the word was sometimes used for ‘drunk’ at about that time, along with drunkener (1400-50), drunkerner (1501) and drunck (±1600); then Dunkelstraße or Темная ул. (Temnaya), dark street (1701, etc.), and whatever the Estonian frontal cortex believed Tunkle ulits (1732) to be. Renamed during the Soviet occupation as Vilde E. (1950-1963) then Vana Tooma (1963-1987). Prior to all this, things get a bit muddled, causing many a sleepless night... Its earliest date (1378) is given by Kivi who says it was known as platea qua itur ad sanctum Nicolaum in opposito putei, or road which goes to Saint Nicholas’, passing by the well (möödudes kaevust) but this looks like a mistake. The main source material here is Nottbeck III II, and my take on this, and I could be wrong, is that Nottbeck was describing the location of a property “opposite the well on the road to Saint Nicholas’”, a point he emphasizes by his comment in the appendix, vielleicht derselbe, perhaps the same one, presumably the Rataskaev well. In which case the platea would refer to Rataskaevu, not Dunkri. In 1439, it was recorded as klene strate bi den sc(h)oboden, alse men geit na deme sternssode, little street near the shoeshops (for more on these, see Raekoja plats) by which you go to the sternssode, and in 1443 as (lutke) strate achter der munte, (little) street behind the mint, logical since by then the mint was at Niguliste 6, stretching north to abut onto Dunkri. However, in the 2nd half of the 15th C, the name started shifting again, and now it seems definitely along the lines of Sternestrate achter munte (1463), sternestrate (1469 & 1489), and strate achter der munte (1478), all variations of sterne street behind the mint, the sterne coming from the name of the well in Rataskaevu.