"unable","(形) ...することができない"
"uncle","(名) おじ"
"under","(前) ...の下に ･ ...に覆われて ･ ...の下を[通って] ･ ...未満で  (副) 下へ[に] ･ 未満に[で]"
"understand","(自他動) 理解する"
"understanding","(名) 理解力 ･ 理解"
"understood","(動) understand の過去形 及び 過去分詞"
"United Kingdom","(名) 連合王国  英国"
"United States","(名) アメリカ合衆国  米国"
"United States of America","(名) アメリカ合衆国  米国"
"unless","(接) もし...でなければ"
"until","(前) ...まで[ずっと] ･ {否定文で}...まで[〜しない]  (接) [...するとき] まで"
"up","(副) [低い所から] 高い所へ  上の方へ  (前) ...を上って ･ ...の上[の方] に  (形) 高い所で[に]"
"upon","(前) → on"
"up to","(前) ...のところまで"
"U.S.","(略) → United States"
"US","(略) → United States"
"U.S.A.","(略) → United States of America"
"USA","(略) → United States of America"
"use","(他動) 使う / (名) 使用 ･ 用途"
"useful","(形) 役に立つ"
"usual","(形) いつもの"
"usually","(副) 普通は"
"useless","(形) 役に立たない"
"unimportant","(形) 重要でない"
"universe","(名) 宇宙"
"universal","(形) 全世界の"
"ultimate","(形) 究極の"
"ultimately","(副) 究極的には"
"ugly","(形) 醜い"
"umbrella","(名) 傘"
"underground","(形) 地下の  (名)(英) 地下鉄 (米  subway) / (副) 地下に"
"underline","(他動) 下に線を引く / (名) 下線"
"undertake","(他動) 引き受ける ･ 企てる"
"underwear","(名) 下着"
"uneasy","(形) 不安な"
"unexpected","(形) 予期しない"
"uniform","(名) 制服  (形) 一様な"
"union","(名) 組合"
"unique","(形) 類のない"
"unit","(名) 単位"
"unite","(自他動) 結合する"
"university","(名) 総合大学"
"unknown","(形) 知られていない"
"unity","(名) 統一性"
"unlike","(前) ...に似ていない"
"upper","(形) 上級の"
"upset","(他動) ろうばいさせる ･ だめにする  (形) 悩んだ  怒った / (名) 転倒 ･ 混乱"
"urban","(形) 都市の"
"urge","(他動) [しきりに] 勧める"
"upword","(副) 上の方へ  (形) 上方への"
"urgent","(形) 緊急の"
"user","(名) 使用者"
"utility","(名) 有用性"
"utilize","(他動) 利用する"
"utopia","(名) 理想社会"
"utter","(他動) 起こる"
"ugliness","(名) 醜いこと"
"uncertain","(形) 確信のない"
"uncommon","(形) 珍しい"
"undergraduate","(名) 学部学生"
"underneath","(前) ...の下に"
"undo","(他動) ほどく ･ 元の状態に戻す"
"unfortunately","(副) 不運にも"
"unfortunate","(形) 不運な"
"unhappy","(形) 不幸な"
"unify","(他動) 統一する"
"unkind","(形) 不親切な"
"unlikely","(形) ありそうにない ･ 考えられない"
"unlucky","(形) 運の悪い"
"unnecessary","(形) 不必要な"
"unusual","(形) 普通でない"
"upright","(形) 直立の ･ 正しい"
"unset","(他動) 狼狽させる ･ ひっくり返す  (形) 悩んだ / (名) 転覆 ･ 混乱"
"upstairs","(副) 上の階へ"
"uptodate","(形) 最新式の"
"upward","(副) 上の方へ   (形) 上方への"
"update","(他動) 最新のものにする / (名) 最新情報"
"used","(形) 使った"
"used to","以前は...であった / (形) ...に慣れている"
"utterly","(副) 全く"
"unreliable","(形) 当てにならない"
"usage","(名) 使い方 ･ 慣習"
"undergo","(他動) 経験する"
"upheaval","(名) 激変"
"urbanization","(名) 都市化"
"utmost","(形) 最大の  (名) 最大限"
"unanimously","(副) 満場一致で"
"unprecedented","(形) 空前の"
"undoubtedly","(形) 確かに"