sporadic 復習

　Security forces in the Somali capital, Mogadishu, have ended a 15-hour siege of a hotel stormed by armed militants.
　The gunmen entered the building after two bombs were detonated in the area. At least 20 people were killed, and it is feared more bodies will be found as security forces search the hotel.
　The Islamist militant group al-Shabab said it had carried out the bombings.
　Two weeks ago, 358 people died in the worst attack in Somalia since the group launched its offensive in 2007.
　The al-Qaeda-linked group denies having any involvement with the 14 October attack, from which another 56 people are still missing. …
　The victims included several policemen who had been stationed close to the hotel's gate, police officer Ali Nur told Reuters news agency.
　Many more people were injured, according to reports. Sporadic gunfire continued inside the hotel throughout the night, witnesses said.

http://www.bbc.com/news/world-africa-41790476

　今回取り上げる語は、sporadic /spərˈædɪk(米), spəˈræd.ɪk(英)/ です。
　まず意味を確認します。『ジーニアス英和大辞典』(大修館)をみると、「点在する、ばらばらの、ちりぢりの; 時折の、(病気が)散発的な(occasional); 孤立した」とあります。この語は sper- (撒き散らす)の意から来ており、sprawl や spray などと同じです。
　次に語源を確認します。Oxford Dictionary of English (2nd Edition Revised)をみると、” late 17th cent. : via medieval Latin from Greek sporadikos, from sporas, sporad- ‘scattered’ ; related to speirein ‘to sow’ ”とあり、scatter が大きく関係しています。
　最後に「時折」を表す語の違いを確認します。よく挙げられる語として、occasional と intermittent があります。それぞれの語をLODGEでみると、occasional は “happening sometimes but not often or regularly” で、intermittent は “stoping and starting often and for short periods”、sporadic は “happening fairly often, but not regularly”となっています。一見日本語だと細かい意味の違いのようですが、このように並べると理解が進みます。(OkaUchi)