Gratitude – Etymological study

Gratitude -

c.1500, from M.L. gratitudo "thankfulness," from L. gratus "thankful, pleasing"

Grateful – ODEE –

Pleasing; thankful xvi. F. grate (xvi) – L. gratus (in the same senses), pp. formation corr. To Skr. gurtas welcome, agreeable, thankful, orig. approved, re. to words of Indo-Iran. And Baltic groups denoting 'praise' (cf. GRACE, GRATIS); the unusual formation with –FUL may have been suggested by It. gradevole pleasing.

Grace –

late 12c., "God's favor or help," from O.Fr. grace "pleasing quality, favor, good will, thanks," from L. gratia "pleasing quality, good will, gratitude," from gratus "pleasing, agreeable," from PIE base *gwer- "to praise, welcome" (cf. Skt. grnati "sings, praises, announces," Lith. giriu "to praise, celebrate," Avestan gar- "to praise"). Sense of "virtue" is early 14c., that of "beauty of form or movement, pleasing quality" is mid-14c. In classical sense, "one of the three sister goddesses (L. Gratiæ, Gk. Kharites), bestowers of beauty and charm," it is first recorded in English 1579 in Spenser. The short prayer that is said before or after a meal (early 13c., until 16c. usually graces) is in the sense of "gratitude." Verb meaning "to show favor" (mid-15c.) led to that of "to lend or add grace to something" (1580s, e.g. grace us with your presence), which is the root of the musical sense in grace notes (1650s). Gracious as an exclamation (1713) is short for gracious God, etc.

Thank (verb) –

O.E. þancian "to give thanks," from P.Gmc. *thankojan (cf. O.S. thancon, O.N. þakka, Dan. takke, O.Fris. thankia, M.Du., Ger. danken "to thank"), from *thankoz "thought, gratitude," from PIE base *tong- "to think, feel." For sense evolution, cf. related O.E. noun þanc, þonc, originally "thought," but by c.1000 "good thoughts, gratitude." The whole group is from the same root as think (q.v.). In ironical use, "to blame," from 1560. Thankful is from O.E. þancfulle; thankless "likely to not be rewarded with thanks" is from c.1547. Thank you is attested from c.1400, short for I thank you. To thank (someone) for nothing is recorded from 1703.

Think –

O.E. þencan "conceive in the mind, think, consider, intend" (past tense þohte, p.p. geþoht), probably originally "cause to appear to oneself," from P.Gmc. *thankjan (cf. O.Fris. thinka, O.S. thenkian, O.H.G. denchen, Ger. denken, O.N. þekkja, Goth. þagkjan); O.E. þencan is the causative form of the distinct O.E. verb þyncan "to seem or appear" (past tense þuhte, pp. geþuht), from P.Gmc. *thunkjan (cf. Ger. dünken, däuchte). Both are from PIE *tong- "to think, feel" which also is the root of thought and thank. The two meanings converged in M.E. and þyncan "to seem" was absorbed, except for archaic methinks "it seems to me."

Ataraxia – Oxford Etymology Dictionary

Disorderliness; (path). Functional irregularity (see locomotor). Xvii. –modL. Ataxia(also used) – Gr. Ataxia, f.a-A-4+taxis order; see TACTIC, -Y3.

Tact – sense of touch xvii; B. faculty of mental perception; C. sens fo propriety, faculty of doing the right thing at the right time xviii. – O.F. tact or L. tactus touch (see TANGENT). In sence C immed. After F. tact (Voltaire 1769)

Tactics – art of deploying forces in battle. Xvii. Repr. modL. tactica (1616 in title of tr. Of AElien's 'Taktike Theoria') – Gr. Ta taktika, n.ppl. of taktikos, f. taktos ordered, arranged, f. base of tassein set in order.