Definitions from Modern Reformation magazine, September-October, 2003.
justification - The legal act whereby God graciously forgives us our sins and reckons us as forevermore righteous in his sight because we have accepted by faith the gift of Christ's perfect earthly obedience and sacrificial death.
propitiation - A righteous God must necessarily be angry against sin but his wrath has been propitiated -- that is, appeased or turned away -- by his Son offering himself as a sinless sacrifice for sin.
substitution - Any situation where one person takes the place of another and thus receives what is due to that other person.
pardon - An act releasing someone from the penalty for wrong-doing. Death is the appropriate penalty for sin but God pardons believers from that penalty because Christ died for them.
imputation - The act of attributing something to someone. In Scripture, there are three primary acts of imputation:
sanctification - Sanctification is the work of God's free grace, whereby we are renewed in the whole man after the image of Christ, and are enabled more and more to die unto sin, and live unto righteousness."
flesh - The active principle of sinfulness in human beings, inherited from Adam and involving all aspects -- mental and physical -- of human nature.
soteriology - The part of Christian theology that deals with how sinful human beings are saved. From the Greek word soteria, meaning deliverance or preservation or salvation.
covenant theology - Theology that takes the key to Scripture to be an understanding of its primary covenants, usually taken to include the eternal covenant of redemption among the three persons of the Trinity to save God's elect, the covenant of works that God struck with Adam, and the covenant of grace between God and the people whom he redeems.
To this list from Modern Ref we would add:
eschatology - From the greek word eschatos, "last or final". Eschatology is the area of Christian theology that deals with the final events in the history mankind and of the world.