1.deficiency n．缺陷(absence of sth. essential; incompleteness)；不足(shortage)

詞根記憶：de+fic(做)+iency--沒做好--缺陷

例:Persons who suffer from a deficiency of the blood enzyme G6PD discover that eating fava beanS triggers hemolytic anemia.

同根詞：deficient(a.不足的；有缺陷的)

2.deficit n.赤字(an excess of expenditure over revenue)

例:A shrinking trade deficit actually added l.57% to GDP this quarter.

派生詞：deficiency(n.缺乏，不足)

3.definition n.定義(a statement expressing the essential nature of sth.)

詞根記憶：來自definite(a.一定的；確切的)

例:A more precise definition of the term "small firm' is crucial to making a conclusive analysis about small firms' roles.

同根詞：definitive(a．確定的；權威性的;n.限定詞)

4.definitive a．確定的(conclusive)；權威性的( authoritative)

詞根記憶：de(加強)+fin(結束)+itiVe(…的)--最終拍板的一權威性的

例:While raising important questions, Eisenstein's essays do not provide definitive answers.

5.deflect v.（使）偏斜,（使）轉舟(to turn aside, deviate)

聯想記憶：de(離開)+flect(彎曲--彎到旁邊--偏斜

例:With no electric charge,a neutrino can cross the entire universe without being absorbed or even deflrected.

6.deform v.使變形(to arter the shape by stress)

詞根記憶：de(表否定)+form（形狀）--使不再是原來的形狀一使變形

例:The stress is severe enough to deform it like putty.

派生詞:deformation(n.變形)

7.defrost v.除霜(to free from ice);解凍(to release from a frozen state)

詞根記憶：de(去掉)+frost(霜)--去除霜--除霜;解凍

例:No attempt was made to defrost the back window.

8.degradation n.退化;降級(decline to a low, destitute, or demoralized state);重落(moral or intellectual decadence)

詞根記憶：來自degrade(v.貶低;降級;退化)

例:Indeed, most analysts believe that some kind of environmental degradation underlies the demise of many extinct salmon populations.

9.degrade n.降低…的身份(to demote)；（使）降解(to decompose)；（使）退化(to decompose)

詞根記憶：de（去掉）+grade(級別)--去掉級別--降低…的身份

例:They argued that the technique had degraded works of art.

10.dehydrate v.（使）脫水(to remove water from; to lose water)

詞根記憶：de(去掉)+hydr(水)+ated--去水的--脫水

例:Retail prices of dehydrated potatoes have declined.

派生詞：dehydration(n.脫水)