From BiblePortal Wikipedia

Vine's Expository Dictionary of OT Words [1]

Sallâch ( סַלָּח , Strong'S #5545), “to forgive.” This verb appears 46 times in the Old Testament. The meaning “to forgive” is limited to biblical and rabbinic Hebrew; in Akkadian, the word means “to sprinkle,” and in Aramaic and Syriac signifies “to pour out.” The meaning of sallâch in Ugaritic is debatable.

The first biblical occurrence is in Moses’ prayer of intercession on behalf of the Israelites: “… It is a stiffnecked people; and [forgive] our iniquity and our sin, and take us for thine inheritance” (Exod. 34:9). The basic meaning undergoes no change throughout the Old Testament. God is always the subject of “forgiveness.” No other Old Testament verb means “to forgive,” although several verbs include “forgiveness” in the range of meanings given a particular context (e.g., naca’ —and ’awon —in Exod. 32:32; kapar —in Ezek. 16:63).

The verb occurs throughout the Old Testament. Most occurrences of sallâch are in the sacrificial laws of Leviticus and Numbers. In the typology of the Old Testament, sacrifices foreshadowed the accomplished work of Jesus Christ, and the Old Testament believer was assured of “forgiveness” based on sacrifice: “And the priest shall make an atonement [for him in regard to his sin]” (Num. 15:25, 28), “And it shall be forgiven him” (Lev. 4:26; cf. vv. 20, 31, 35; 5:10, 13, 16, 18). The mediators of the atonement were the priests who offered the sacrifice. The sacrifice was ordained by God to promise ultimate “forgiveness” in God’s sacrifice of His own Son. Moreover, sacrifice was appropriately connected to atonement, as there is no forgiveness without the shedding of blood (Lev. 4:20; cf. Heb. 9:22).

Out of His grace, God alone “forgives” sin. The Israelites experienced God’s “forgiveness” in the wilderness and in the Promised Land. As long as the temple stood, sacrificial atonement continued and the Israelites were assured of God’s “forgiveness.” When the temple was destroyed and sacrifices ceased, God sent the prophetic word that He graciously would restore Israel out of exile and “forgive” its sins (Jer. 31:34).

The psalmist appealed to God’s great name in his request for “forgiveness”: “For thy name’s sake, O Lord, pardon mine iniquity; for it is great” (Ps. 25:11). David praised God for the assurance of “forgiveness” of sins: “Bless the Lord, O my soul … , who forgiveth all thine iniquities …” (Ps. 103:2-3). The Old Testament saints, while involved in sacrificial rites, put their faith in God.

In the Septuagint, sallâch is most frequently translated by hileos einai —(“to be gracious; be merciful”), hilaskesthai (“to propitiate, expiate”) and apievai (“to forgive, pardon, leave, cancel”). The translation “to forgive” is found in most English versions (Kjv, Rsv, Nasb, Niv ) and at times also “to pardon” (Kjv, Rsv )

King James Dictionary [2]

FORGIVE, forgiv'. pret. forgave pp. forgiven. L. remitto. See Give.

1. To pardon to remit, as an offense or debt to overlook an offense, and treat the offender as not guilty. The original and proper phrase is to forgive the offense, to send it away, to reject it, that is, not to impute it, put it to the offender. But by an easy transition, we also use the phrase, to forgive the person offending.

Forgive us our debts.

If we forgive men their trespasses, your heavenly father will also forgive you.  Matthew 6 .

As savages never forget a favor, so they never forgive an injury.

It is to be noted that pardon, like forgive, may be followed by the name or person, and by the offense but remit can be followed by the offense only. We forgive or pardon the man, but we do not remit him.

2. To remit as a debt, fine or penalty.

Webster's Dictionary [3]

(1): ( v. t.) To give wholly; to make over without reservation; to resign.

(2): ( v. t.) To cease to feel resentment against, on account of wrong committed; to give up claim to requital from or retribution upon (an offender); to absolve; to pardon; - said of the person offending.

(3): ( v. t.) To give up resentment or claim to requital on account of (an offense or wrong); to remit the penalty of; to pardon; - said in reference to the act forgiven.