Bedeutet der Name des höchsten afrikanischen Berges, des «Kilimandscharo», nach dem wahrhaft ironischen Understatement des Kiswahili, der am meisten gesprochenen Sprache in Ostafrika, «kleiner Hügel von Njaro»? Oder empfiehlt es sich, seine Spitze – als «den höchsten Punkt afrikanischer und deutscher Erde» – die «Kaiser-Wilhelm-Spitze» zu nennen, wie es der Deutsche Hans Meyer bei seiner Erstbesteigung am 6. Oktober 1889 unter Aufpflanzung der deutschen Fahne und, begleitend dazu, der dreimaligen Ausrufung eines kräftigen «Hurra» tat? / Ludger Lütkehaus, NZZ 13.9.
Wikipedia bringt je nach Sprache unterschiedliche Berichte (es lohnt sich auch in die Details zu gehen: was nicht nur für Hölderlin-Fassungen gilt):
An alternative theory is as follows: On November 10, 1848, the German missionary Rebmann wrote in his diary: „This morning we discerned the Mountains of Jagga more distinctly than ever.“ Jagga was the pronunciation of Chagga by Europeans. Kilimanjaro may also be the European pronunciation of the Chagga phrase that „Kile-lema-irho“, meaning „we failed to climb it“ in Kiuru, Kioldimoshi, Kimarangu, Kivunjo, Kikibosho, Kimachame and Kirombo, Kichagga in general. If so, name itself, Kile-lema-irho/Kilimanjaro, would have been the Chagga way of explaining to kyasaka (newcomers) when they asked about the shining mountain top of Kibo and Mawenzi Peak. Kibo peak is more visible from the Kibosho Area, and Mawenzi from Maranu.
In 1861 von der Decken climbed Mt. Kilimanjaro together with Richard Thornton (1838-1863), „who got no farther than 8,200 feet“ (2,500 metres). In 1862 von der Decken tried a second time together with Otto Kersten. They reached a hight of 14,000 feet (4,280 metres). 
In the 1880s, the mountain, at that time spelled Kilima-Ndscharo in German following the Swahili name components, became a part of German East Africa after Karl Peters had persuaded local chiefs to sign treaties (a common story that Queen Victoria gave the mountain to her grandson Kaiser Wilhelm II is not true). In 1889 the peak of Kibo was named „Kaiser-Wilhelm-Spitze“ („Kaiser Wilhelm peak“) by Hans Meyer, on the first ascent to the summit on 5 October 1889.  That name was used until 1918, when after World War I the German colonies were handed over to the British empire. When British-administeredTanganyika gained its independence in 1961, the peak was named „Uhuru peak“, meaning „Freedom peak“ in Swahili.
Hans Meyer, a German professor was the first European to conquer Mount Kilimanjaro, accompanied by an Austrian mountaineer named Ludwig Purtscheller and a Marangu Army Scout named Kinyala Lauwo. They completed the climb on the 5 October, 1889. 
The Ki- prefix in Swahili has several underlying meanings. The old Ka- diminutive noun prefix (found now only as Kadogo – a small degree), merged with the Ki class. One of its meanings was to also describe something unique of its kind: Kilima, a single peak, as opposed to Mlima, which would better describe a mountain range or undulating country. Several other mountains also bear this prefix, such as Kilima Mbogo (Buffalo Mountain), just north of Nairobi in Kenya. People with disabilities are also placed in this class, not so much as a diminutive idea; but a unique condition they possess: a blind or a deaf person, Kipofu and Kiziwi. This prefix „Ki-“ in no way implies a derogatory sense. The name Kibo in Kichagga means „spotted“ and refers to rocks seen on snowfields. (English)