名词reflection有如下六个典型义项。
义项1：物理意义的反弹
声光电磁热从在物体或介质表面的反弹，即“反射”，这是动作本身，不可数名词，如
【例句1】There is reflection of heat from the metal surface. （金属表面反射热量。）[牛津高级学者辞典]
【例句2】He put silver foil around the fire to increase heat reflection.（他在火周围放了银箔，以增加热反射。）[剑桥高级学者辞典]
【例句3】This is only visible at certain angles of reflection. （这仅在某些反射角度可见。）[剑桥高级学者辞典]
【例句4】The laser’s angle of reflection is 30 degrees. （激光的反射角为30度。）[剑桥高级学者辞典]
义项2：反射后结果
经光滑表面或水表面反射后所成的像，即映像、映照出的影像，相当于物，可数名词，如
【例句5】Can you see your reflection in the glass? （你能看到镜子里的自己吗？）[朗文当代英语词典]
【例句6】Meg stared at her reflection in the bedroom mirror. （梅格盯着卧室镜子里的自己。）[柯林斯高级学者辞典]
【例句7】He admired his reflection in the mirror. （他欣赏自己在镜子里的倒影。）[牛津高级学者辞典]
【例句8】In Greek mythology, Narcissus fell in love with his own reflection in a pool of water. （在希腊神话中，纳西索斯爱上了自己在水池中的倒影。）[剑桥高级学者辞典]
【例句9】She was looking at her reflection in the mirror. （她看着镜子里的自己。）[剑桥高级学者辞典]
义项3：思绪的反弹
从物理反弹的引申为思绪在脑壳内弹来弹去，即仔细思考、沉思、回忆，往往经历了很长一段时间，这是动作，不可数名词。品读例句，
【例句10】A week off would give him time for reflection. （休息一周会让他有时间反复思考。）[牛津高级学者辞典]
【例句11】After days of reflection she decided to write back. （经过几天的深思，她决定回信。）[柯林斯高级学者辞典]
【例句12】A moment‘s reflection will show the stupidity of this argument. （稍作思考，就会发现这个论点的愚蠢。）[朗文当代英语词典]
不过，有时候也用复数reflections表达“思绪万千”，如
【例句13】He paused, absorbed by his reflections. （他停顿了一下，全神贯注地思考着。 ）[柯林斯高级学者辞典]
所以有词典将此义项标为variable noun（单复皆可的名词）。
义项4：思绪反弹的结果
就某主题或话题，被书面或口头表达出来的思考结果，往往为复数形式(表达不知一个)，如
【例句14】In his latest collection of poems readers are confronted with a series of reflections on death. （在他最新的诗集中，读者面对着一系列关于死亡的思考。）[柯林斯高级学者辞典]
【例句15】After 30 years as a judge, her reflections on/about justice were well worth listening to.（在担任法官30年后，她对正义的思考非常值得一听。）[剑桥高级学者辞典]
义项5：广义反射
根据物理反射所形成的像，就能提供判断原物的情状，因此比拟物理反射，reflection也指对某状态、状况、事物本质的反映或显示，这是结果，但侧重其抽象归一，所以多为仅单数名词。品读例句，
【例句16】Your clothes are often a reflection of your personality. （你的衣服往往反映了你的个性。）[牛津高级学者辞典]
【例句17】His poor job performance is a reflection of his lack of training.（他糟糕的工作表现反映了他缺乏训练。）[剑桥高级学者辞典]
【例句18】I don’t believe these exam results are a true reflection of your abilities.（我不相信这些考试成绩是你能力的真实反映。）[剑桥高级学者辞典]
【例句19】Inhibition in adulthood is a reflection of a person’s experiences as a child. （成年后的抑制是一个人小时候经历的反映。）[柯林斯高级学者辞典]
【例句20】This account is only a pale reflection of the true state of affairs. （这种说法只是对真实情况的苍白反映。）[牛津高级学者辞典]
【例句21】The fact that soldiers are on the streets is a reflection of how terrified the government is.（士兵们流落街头的事实反映了政府有多么害怕。）[剑桥高级学者辞典]
【例句22】The grief after her death was a reflection of the great love that people felt for her.(她离世后，人们的悲痛之情，正是大家对她深沉爱意的真切写照。)[剑桥高级学者辞典]
义项6：义项5的狭义
指文字、作品或发言的记录、表达，可数名词，如
【例句23】His speech was an accurate reflection of the public mood.（他的演讲准确地表达了公众的情绪。）[朗文当代英语词典]
【例句24】The film is a reflection of the violence that pervades American culture. （这部电影反映了弥漫在美国文化中的暴力。）[剑桥高级学者辞典]
【例句25】Her novel is an accurate reflection of life in post-war Spain.(她的小说准确地记录了战后西班牙的生活。)[剑桥高级学者辞典]
【例句26】The article is an accurate reflection of events that day.（这篇文章准确地复现了那天发生的事情）[牛津高级学者辞典]