6 letters:
amalie, gamily

7 letters:
familie, hammily

8 letters:
clammily

9 letters:
profamily, subfamily

10 letters:
musical.ly, pro-family, stepfamily

11 letters:
macrofamily, multifamily

13 letters:
single-family

5 letters:
ataxy, agony, laxly

6 letters:
apogee, sanity, cavity, galaxy, laxity, apathy, satiny, abbacy, antony, lazily, anomie, saxony, malady, canopy, vanity, agassi, cagily, mccabe

7 letters:
happily, capably, nastily, anthony, tragedy, opacity, balcony, gascony, balmily, fallacy, gravity, anatomy, rapidly, faculty, calumny, valency, atrophy, amnesty, majesty, edacity, maggoty, angrily, cadency, analogy, academy, sassaby, agilely, tammany, reality, fantasy, handily, tastily, cannily, alchemy, affably, manatee, cavalry, rackety, faddily, inanity, natalie, ratafee, tattily, wackily

8 letters:
tonality, tapestry, axletree, modality, casually, phantasy, scammony, chastity, vitality, craftily, banditry, fugacity, casualty, actually, diastole, alacrity, sagacity, gravelly, travesty, audacity, nascency, damnably, locality, nasality, absently, vivacity, calamity, legality, mangabey, scantily, insanity, totality, flashily, rhapsody, falconry, tangency, passably, patently, rapacity, capacity, gadgetry, valiancy, basketry, sodality, manfully, finality, randomly, morality, examinee, salacity, voracity, strategy, rascally, chattily, jaggedly, lambency, pallidly, raggedly, sacristy, scrabbly, urbanity

9 letters:
sexuality, gallantly, cabinetry, formality, blasphemy, unhappily, brutality, concavity, actuality, depravity, rampantly, unreality, captaincy, mentality, joviality, patchouli, mortality, stagnancy, geniality, bashfully, halfpenny, valiantly, naturally, mammalogy, callously, frugality, pugnacity, anxiously, philately, gallantry, scrappily, profanity, lethality, animality, pageantry, normality, tactfully, carnality, plangency, baptistry, irreality, laughably, loquacity, rascality

10 letters:
cordiality, thankfully, triviality, asexuality, factuality, rationally, araliaceae, compatibly, incapacity, liberality, baptistery, neutrality, inhumanity, nationally, bankruptcy, anastrophe, sensuality, generality, musicality, partiality, chaplaincy, dextrality, logicality, lyricality, severality, spatiality, tactlessly, typicality, unmanfully

11 letters:
fractiously, criticality, abnormality, catastrophe, alismatidae, pertinacity, nationality, practically, commonality, elaborately, disassembly, hylobatidae, hospitality, bisexuality, unnaturally, financially, atypicality, dapple-grey, physicality, prodigality, temporality, verticality

12 letters:
perspicacity, congeniality, unilaterally, subnormality, bilaterality, universality, practicality, spirituality, irrationally, juglandaceae, municipality, philanthropy, clinodactyly, conviviality, corporeality, dappled-grey, ephemerality, essentiality, illiberality, illogicality, incompatibly, neuroanatomy, polytonality, potentiality, sinistrality, untypicality, whimsicality

13 letters:
homosexuality, substantially, immateriality, irrationality, amaranthaceae, underhandedly, artificiality, aerophilately, horizontality, reciprocality, theatricality

14 letters:
superficiality, understandably, incorporeality, satisfactorily, substantiality, ambystomatidae, territoriality, dimensionality, cylindricality, impracticality, inessentiality, nonsensicality, sesquipedality, uncongeniality

15 letters:
confidentiality, internationally, psychosexuality

16 letters:
circumstantially, insubstantiality, unsatisfactorily, ununderstandably

18 letters:
one-dimensionality, two-dimensionality

20 letters:
third-dimensionality, three-dimensionality