Wisdom
Wisdom is both the knowledge of and judgment about “divine things” and the ability to judge and direct human affairs according to divine truth (I/I.1.6; I/II.69.3; II/II.8.6; II/II.45.1–5).
Understanding
Understanding is penetrating insight into the very heart of things, especially those higher truths that are necessary for our eternal salvation—in effect, the ability to “see” God (I/I.12.5; I/II.69.2; II/II.8.1–3).
Counsel
Counsel allows a man to be directed by God in matters necessary for his salvation (II/II.52.1).
Fortitude
Fortitude denotes a firmness of mind in doing good and in avoiding evil, particularly when it is difficult or dangerous to do so, and the confidence to overcome all obstacles, even deadly ones, by virtue of the assurance of everlasting life (I/II.61.3; II/II.123.2; II/II.139.1).
Knowledge
Knowledge is the ability to judge correctly about matters of faith and right action, so as to never wander from the straight path of justice (II/II.9.3).
Piety
Piety is, principally, revering God with filial affection, paying worship and duty to God, paying due duty to all men on account of their relationship to God, and honoring the saints and not contradicting Scripture. The Latin word pietas denotes the reverence that we give to our father and to our country; since God is the Father of all, the worship of God is also called piety (I/II.68.4; II/II.121.1).
Fear of God
Fear of God is, in this context, “filial” or chaste fear whereby we revere God and avoid separating ourselves from him—as opposed to “servile” fear, whereby we fear punishment (I/II.67.4; II/II.19.9).
Reference
See https://www.catholic.com/magazine/print-edition/the-seven-gifts-of-the-holy-spirit