二

hookworm

one country, two systems (Chinese policy allowing for areas such as Hong Kong to maintain their own economic and administrative systems)

hook turn

Physics

second law of thermodynamics

Chemistry

silicon dioxide; silica

Shinto

two bows, two claps, and a third bow (common form of worshipping at a shrine)

double-dealer; timeserver; moving back and forth between two sides in a conflict

assistant chief of staff, g2

conjugation (inflection, declension) of nidan verbs (resulting in a stem of either "e" or "u" for every conjugation)

Grammar

second-person pronoun

Music

half note; minim

Military

airman third class (JASDF)

Military

first lieutenant (JGSDF)

polarisation

every third

you are what you eat; slogan encouraging consumption of local seasonal foods for one's health; indivisibility of the body and the land (because the body is made from food and food is made from the land)

double standard

to give birth

half; cutting in two

Computing

binary search tree

quadratic curve

biceps femoris muscle

Buddhism

the road to paradise is a white road between two rivers, one of water (wrath) and one of fire (greed)

doing twice the work; duplication of work